Need Help Building a Cleveland

Need Help Building a Cleveland

Joined: December 6th, 2010, 8:10 pm

December 10th, 2010, 7:13 pm #1

I have a 1970 Mach 1 that I bought so my dad and I can spend time together doing something we both enjoy. It's originally a 351C 4bbl (M code) with a close ratio 4-speed and a Shaker hood. It currently has a really strong running 351W under a stock hood. I would like to build up a correctly date coded 351C block, exhaust manifolds, intake, etc. that came with the car. This included 2bbl heads as the previous owner had heard that they were "the hot ticket". I personally would like the car to be as close to stock as possible but I drive a lot so I'm willing to make changes for drivability and reliability.

My basic requirements are:
1. Fit/work with the stock shaker setup
2. Look stock(ish) - so no blocky aluminum heads, tall intakes, or headers
3. Great street manners (8-10k miles per year in a mix of city streets, back roads, and highways)
4. Set it and forget it - I like to drive not fiddle around under the hood
5. It would be nice if it had some unexpected (hidden) power - dad has to keep up with my 340 Challenger

Dad had a 69 Torino with a 351W and 4-speed. He remembers test driving a 351C Mustang in 1970 and wasn't impressed. That was 40 years ago so I have no other details. He says the 351W currently in the Mach 1 feels faster than his car so I would like to at least improve upon that. If I can build it stock and accomplish my goals then that's great but I have to build something so any extra improvements are welcome.

If I buy a set of closed chamber 4bbl heads should I worry about the compression ratio? I can get 93 octane fuel but it scares me a little to run that high of compression with iron heads.

Since the 4bbl heads flow so well, I was wondering if a mild stroker kit would make use of the flow while adding some low end torque? Would the stock intake and exhaust offset any gains?

Would the "Aussie" heads or any of the aftermarket heads provide enough of an advantage to consider using them instead? Again, not a race engine.

I know cam technology has come a long way. What would be the best choice for my application?

An additional option: a local Mustang restoration shop has an already built 351C that is supposedly date correct for my car. I need to verify details but if everything is truly date coded then it should have closed chamber 4bbl heads already. The engine builder used a cam that he found to work really well but I don't have the specs handy. I'm assuming it is a stock rebuild other than the cam. Asking price is $2,500 intake to pan (I have a carb and exhaust manifolds). It looks like it will cost $1,700-2,000 to build mine in a similar fashion and I'd still have to purchase the 4bbl heads. I can sell off some parts to offset the cost of buying it though.

Suggestions?

Troy
Quote
Like
Share

Joined: September 17th, 2009, 3:12 am

December 10th, 2010, 7:49 pm #2

What is the compression ratio of the one already built? If you want to set it and forget it on 93 octane, then I'd stay under 10:1 ratio. I had a similar build, and used the KB dished pistons to lower the compression. There are plenty of cams to choose from, it all depends on the TC stall speed, and rear end gears. I'd go with a minimum of 3.50 gears, but recommend 3.90. Believe me when I say that it purrs at 3500 RPM cruising speed. I started with 3.50, and kept going up.
Quote
Like
Share

Joined: October 1st, 2004, 8:05 pm

December 10th, 2010, 8:10 pm #3

I have a 1970 Mach 1 that I bought so my dad and I can spend time together doing something we both enjoy. It's originally a 351C 4bbl (M code) with a close ratio 4-speed and a Shaker hood. It currently has a really strong running 351W under a stock hood. I would like to build up a correctly date coded 351C block, exhaust manifolds, intake, etc. that came with the car. This included 2bbl heads as the previous owner had heard that they were "the hot ticket". I personally would like the car to be as close to stock as possible but I drive a lot so I'm willing to make changes for drivability and reliability.

My basic requirements are:
1. Fit/work with the stock shaker setup
2. Look stock(ish) - so no blocky aluminum heads, tall intakes, or headers
3. Great street manners (8-10k miles per year in a mix of city streets, back roads, and highways)
4. Set it and forget it - I like to drive not fiddle around under the hood
5. It would be nice if it had some unexpected (hidden) power - dad has to keep up with my 340 Challenger

Dad had a 69 Torino with a 351W and 4-speed. He remembers test driving a 351C Mustang in 1970 and wasn't impressed. That was 40 years ago so I have no other details. He says the 351W currently in the Mach 1 feels faster than his car so I would like to at least improve upon that. If I can build it stock and accomplish my goals then that's great but I have to build something so any extra improvements are welcome.

If I buy a set of closed chamber 4bbl heads should I worry about the compression ratio? I can get 93 octane fuel but it scares me a little to run that high of compression with iron heads.

Since the 4bbl heads flow so well, I was wondering if a mild stroker kit would make use of the flow while adding some low end torque? Would the stock intake and exhaust offset any gains?

Would the "Aussie" heads or any of the aftermarket heads provide enough of an advantage to consider using them instead? Again, not a race engine.

I know cam technology has come a long way. What would be the best choice for my application?

An additional option: a local Mustang restoration shop has an already built 351C that is supposedly date correct for my car. I need to verify details but if everything is truly date coded then it should have closed chamber 4bbl heads already. The engine builder used a cam that he found to work really well but I don't have the specs handy. I'm assuming it is a stock rebuild other than the cam. Asking price is $2,500 intake to pan (I have a carb and exhaust manifolds). It looks like it will cost $1,700-2,000 to build mine in a similar fashion and I'd still have to purchase the 4bbl heads. I can sell off some parts to offset the cost of buying it though.

Suggestions?

Troy
If I had your goals, this would be my shopping list ...

351C 4V quench chamber heads (D0AE or D1AE castings) ... ported.
Forged, flat top, full round skirt pistons, compression height set for 10.0:1 compression
Blue Thunder dual plane intake manifold (I believe guys use shakers with these)
Holley 750 cfm HP street carburetor, mechanical secondary #0-82751 or vacuum secondary #0-82750
Modern breakerless ignition with rev limiter & ignition retard during starting
Headers, 2 1/2" tailpipes, free flowing mufflers

Cam: hydraulic (flat or roller) overlap around 55°, intake valve closes around 70° ABDC. 110° lobe centers. Valve lift in the range of 0.570" to 0.630" depending upon the type of cam and the cam grinder. Lunati VooDoo cam, Comp Cams Extreme Energy cam, or I can spec a nice custom one for you. 450 BHP or more IF you use headers.

Suitable valve train: Yella Terra YT6015 rocker arms, Ti intake valves, hollow stem stainless exhaust valves, Ti retainers, matching springs, stiff push rods with 0.040" restrictor tips.

Paint or powder coat the Blue Thunder intake Ford Blue, the motor will look 100% stock except for the headers, but will make 450 BHP with good drivability. The headers can be ceramic or Jet Hot coated which will keep them looking nice and remove some heat from the engine compartment. I would suggest 3.89:1 gears to put the 4V heads in the rpm range where they like to operate (assuming 26" OD tires)

-G

FYI this is the same motor we built 40 years ago, except for 3 things available today that weren't available then: (1) better cam lobes (2) Yella Terra rocker arms (3) Holley HP carburetors. In the 70s & 80s you had to pay somebody to set the Holley carburetor up, today you just buy it off-the-shelf. The modern cam lobes allow us to make impressively better power with the same overlap & intake valve closing specs. Without resorting to the expense of alloy heads or a stroker kit, we can build a 351 cubic inch motor making 450 BHP that retains factory style drivability with what is essentially a valve train upgrade.

Last edited by gpence on December 11th, 2010, 7:14 am, edited 1 time in total.
Quote
Like
Share

Joined: March 9th, 2004, 3:37 pm

December 10th, 2010, 8:53 pm #4

I have a 1970 Mach 1 that I bought so my dad and I can spend time together doing something we both enjoy. It's originally a 351C 4bbl (M code) with a close ratio 4-speed and a Shaker hood. It currently has a really strong running 351W under a stock hood. I would like to build up a correctly date coded 351C block, exhaust manifolds, intake, etc. that came with the car. This included 2bbl heads as the previous owner had heard that they were "the hot ticket". I personally would like the car to be as close to stock as possible but I drive a lot so I'm willing to make changes for drivability and reliability.

My basic requirements are:
1. Fit/work with the stock shaker setup
2. Look stock(ish) - so no blocky aluminum heads, tall intakes, or headers
3. Great street manners (8-10k miles per year in a mix of city streets, back roads, and highways)
4. Set it and forget it - I like to drive not fiddle around under the hood
5. It would be nice if it had some unexpected (hidden) power - dad has to keep up with my 340 Challenger

Dad had a 69 Torino with a 351W and 4-speed. He remembers test driving a 351C Mustang in 1970 and wasn't impressed. That was 40 years ago so I have no other details. He says the 351W currently in the Mach 1 feels faster than his car so I would like to at least improve upon that. If I can build it stock and accomplish my goals then that's great but I have to build something so any extra improvements are welcome.

If I buy a set of closed chamber 4bbl heads should I worry about the compression ratio? I can get 93 octane fuel but it scares me a little to run that high of compression with iron heads.

Since the 4bbl heads flow so well, I was wondering if a mild stroker kit would make use of the flow while adding some low end torque? Would the stock intake and exhaust offset any gains?

Would the "Aussie" heads or any of the aftermarket heads provide enough of an advantage to consider using them instead? Again, not a race engine.

I know cam technology has come a long way. What would be the best choice for my application?

An additional option: a local Mustang restoration shop has an already built 351C that is supposedly date correct for my car. I need to verify details but if everything is truly date coded then it should have closed chamber 4bbl heads already. The engine builder used a cam that he found to work really well but I don't have the specs handy. I'm assuming it is a stock rebuild other than the cam. Asking price is $2,500 intake to pan (I have a carb and exhaust manifolds). It looks like it will cost $1,700-2,000 to build mine in a similar fashion and I'd still have to purchase the 4bbl heads. I can sell off some parts to offset the cost of buying it though.

Suggestions?

Troy
Hi Troy,

Welcome to the forum. I posted a similar question about 5 years ago when I started building an engine for my 70 ranchero (m-code, 4-speed). Wanted it to look stock. Wanted to use the stock intake and exhaust manifolds. I built a balanced rotating assembly with the stock crank, rods (ARP bolts), and TRW forged flattops (2377). I decked the block to get the pistons at -0.005". I put in one piece stainless valves and got a good valvejob. Called Reed cams and told them everything, they spec'd a 228/236 544/566 hydro flat tappet on 108. I took my time and set up the rocker geometry correctly using Harland Sharp roller rockers. Holley 750VS on the stock intake. Dual exhaust with the stock exhaust manifolds. Wanted stock so tried to keep the stock distributor and installed a crane conversion.

The motor was a turd. Dynojet dyno at 240rwhp. Very dissapointing. Added a torker intake and an Accel distibutor. Got it to 265rwhp.

Then I added headers, 2.5" exhaust and a holley 700DP. Completely different engine. Dynojet dyno at 330rwhp.

I'm pretty sure the headers were the key. The Cleveland likes to breathe.

I know you want it to look stock. I did too. I ended up being happy with "period correct" and 65 more ponies.

If you really want to keep the exhaust manifolds, then you are going to have to put on a very good exhaust system, and importantly, get the right cam. Reversion and contamination of the intake charge will be the big problem with performance cams off the shelf. Make sure to keep the overlap to a minimum. Before I changed to headers, the intake track was soot covered and even the bottom of the carb was dark.

Good luck,
James P.
Quote
Like
Share

Joined: December 6th, 2010, 8:10 pm

December 10th, 2010, 10:32 pm #5

What is the compression ratio of the one already built? If you want to set it and forget it on 93 octane, then I'd stay under 10:1 ratio. I had a similar build, and used the KB dished pistons to lower the compression. There are plenty of cams to choose from, it all depends on the TC stall speed, and rear end gears. I'd go with a minimum of 3.50 gears, but recommend 3.90. Believe me when I say that it purrs at 3500 RPM cruising speed. I started with 3.50, and kept going up.
are 3.90 I believe (that's what the tag calls for if I remember right). Need to verify that. Dad thinks it revs too high on the highway trying to keep up with me at 75 mph in the Charger with 3.23 gears and 28" tires. I don't think it sounds too terrible but I guess he blew his up one time (I suspect he was going faster than 75).

Troy
Quote
Like
Share

Joined: December 6th, 2010, 8:10 pm

December 10th, 2010, 10:39 pm #6

If I had your goals, this would be my shopping list ...

351C 4V quench chamber heads (D0AE or D1AE castings) ... ported.
Forged, flat top, full round skirt pistons, compression height set for 10.0:1 compression
Blue Thunder dual plane intake manifold (I believe guys use shakers with these)
Holley 750 cfm HP street carburetor, mechanical secondary #0-82751 or vacuum secondary #0-82750
Modern breakerless ignition with rev limiter & ignition retard during starting
Headers, 2 1/2" tailpipes, free flowing mufflers

Cam: hydraulic (flat or roller) overlap around 55°, intake valve closes around 70° ABDC. 110° lobe centers. Valve lift in the range of 0.570" to 0.630" depending upon the type of cam and the cam grinder. Lunati VooDoo cam, Comp Cams Extreme Energy cam, or I can spec a nice custom one for you. 450 BHP or more IF you use headers.

Suitable valve train: Yella Terra YT6015 rocker arms, Ti intake valves, hollow stem stainless exhaust valves, Ti retainers, matching springs, stiff push rods with 0.040" restrictor tips.

Paint or powder coat the Blue Thunder intake Ford Blue, the motor will look 100% stock except for the headers, but will make 450 BHP with good drivability. The headers can be ceramic or Jet Hot coated which will keep them looking nice and remove some heat from the engine compartment. I would suggest 3.89:1 gears to put the 4V heads in the rpm range where they like to operate (assuming 26" OD tires)

-G

FYI this is the same motor we built 40 years ago, except for 3 things available today that weren't available then: (1) better cam lobes (2) Yella Terra rocker arms (3) Holley HP carburetors. In the 70s & 80s you had to pay somebody to set the Holley carburetor up, today you just buy it off-the-shelf. The modern cam lobes allow us to make impressively better power with the same overlap & intake valve closing specs. Without resorting to the expense of alloy heads or a stroker kit, we can build a 351 cubic inch motor making 450 BHP that retains factory style drivability with what is essentially a valve train upgrade.

Guess I need to go with headers. Dad is always going on about the Boss 351 and they ran pretty good with factory manifolds so I was hoping I could get away with it. This is by no means a concourse show car but I didn't want it to end up looking like a race car. Do headers on these engines cause problems like burnt wires or hiding the plugs?

Looking up the Blue Thunder intakes now.

I'm pretty lost when it comes to cams. Thanks for the info.

Troy
Quote
Like
Share

Joined: December 6th, 2010, 8:10 pm

December 10th, 2010, 10:43 pm #7

Hi Troy,

Welcome to the forum. I posted a similar question about 5 years ago when I started building an engine for my 70 ranchero (m-code, 4-speed). Wanted it to look stock. Wanted to use the stock intake and exhaust manifolds. I built a balanced rotating assembly with the stock crank, rods (ARP bolts), and TRW forged flattops (2377). I decked the block to get the pistons at -0.005". I put in one piece stainless valves and got a good valvejob. Called Reed cams and told them everything, they spec'd a 228/236 544/566 hydro flat tappet on 108. I took my time and set up the rocker geometry correctly using Harland Sharp roller rockers. Holley 750VS on the stock intake. Dual exhaust with the stock exhaust manifolds. Wanted stock so tried to keep the stock distributor and installed a crane conversion.

The motor was a turd. Dynojet dyno at 240rwhp. Very dissapointing. Added a torker intake and an Accel distibutor. Got it to 265rwhp.

Then I added headers, 2.5" exhaust and a holley 700DP. Completely different engine. Dynojet dyno at 330rwhp.

I'm pretty sure the headers were the key. The Cleveland likes to breathe.

I know you want it to look stock. I did too. I ended up being happy with "period correct" and 65 more ponies.

If you really want to keep the exhaust manifolds, then you are going to have to put on a very good exhaust system, and importantly, get the right cam. Reversion and contamination of the intake charge will be the big problem with performance cams off the shelf. Make sure to keep the overlap to a minimum. Before I changed to headers, the intake track was soot covered and even the bottom of the carb was dark.

Good luck,
James P.
I did actually search but I guess I missed that. All my cars seem to have the same problem - lack of airflow. Headers and an intake have been a HUGE improvement on all of them. Oh well, minor mods are OK I suppose.

Is there a stockish looking 2.5" exhaust system available?

I better figure out the exhaust before the cam.

Thanks,
Troy
Quote
Like
Share

Joined: December 6th, 2010, 8:10 pm

December 10th, 2010, 10:45 pm #8

What is the compression ratio of the one already built? If you want to set it and forget it on 93 octane, then I'd stay under 10:1 ratio. I had a similar build, and used the KB dished pistons to lower the compression. There are plenty of cams to choose from, it all depends on the TC stall speed, and rear end gears. I'd go with a minimum of 3.50 gears, but recommend 3.90. Believe me when I say that it purrs at 3500 RPM cruising speed. I started with 3.50, and kept going up.
I'll be calling the guy with the motor this evening to see if I can get some better (more accurate) specs. I'm reasonably certain the motor is stock but now I'm thinking they probably tried a few tricks to make it more livable.

Troy
Quote
Like
Share

Joined: October 1st, 2004, 8:05 pm

December 10th, 2010, 10:55 pm #9

Keep in mind, Ford's advertised compression ratio for the 1970 & 1971 M code motors was not accurate. In 1970 they advertised 11.0:1 compression ratio, it was actually 10.0:1, in 1971 they advertised 10.7:1 compression ratio, it was actually 9.7:1.

-G

Quote
Like
Share

Joined: September 17th, 2009, 3:12 am

December 11th, 2010, 12:07 am #10

I did actually search but I guess I missed that. All my cars seem to have the same problem - lack of airflow. Headers and an intake have been a HUGE improvement on all of them. Oh well, minor mods are OK I suppose.

Is there a stockish looking 2.5" exhaust system available?

I better figure out the exhaust before the cam.

Thanks,
Troy
There is a difference between stock and just looking stock. nobody will ever see the exhaust, so you can do whatever and it still looks stock. Paint the intake blue and it looks stock. If you have the stock air cleaner housing then you won't be able to see the intake anyways. I'd just save some money and go from the headers, to glasspacks, to turndowns, done.
Quote
Like
Share