[CantedValve]

I’m hoping I get constructive feedback on this forum vs. others I tried.

I think I am doing the right thing, but I want more eyes on it. Here’s what I’m doing:

• 1970 Mustang with full interior. This is first a good weather daily driver. We will do some drag racing with it, but for fun and not competitively. Pump gas capable
• Toploader 4 speed with between 3.50 and 3.89 gears out back
• 351C engine with flattop pistons, stock stroke, and zero deck. Quench height at or below 0.041”. Zero deck via shaving the deck or ordering the right comp height pistons
• Edelbrock Air Gap intake, or Performer intake if the Air Gap won’t fit under the shaker.
• Holley mechanical secondary carburetor
• Hydraulic roller camshaft
• Trick Flow 195cc aluminum heads

The questions are, which heads and camshaft. The variable on the heads is chamber size - 62cc or 72cc. The camshaft will have to be picked to work with the heads.

• 72cc heads yield a 9.8:1 static compression ratio. The highest effective (dynamic) compression ratio I can get is around 8.0:1 with a cam that closes intake at 61 degrees. Cam would max out at 6000, which is fine by us.
• 62cc heads yield 10.9:1 static compression ratio. The lowest effective compression ratio I can manage would be around 8.3:1 with a cam that closes the intake at 69 and operates (mostly) below 6500.

Effective CR is measured seat to seat. The original Boss 351 was somewhere around 7.9:1 effective compression, but started at 11:1

This is my first ground up engine build. The rest of my experience has been with stock components. Never even had machine work done before. I want to get as much as I can out of my parts safely. I’m leaning to the 72cc chamber and cam to match, but… if… but… if…. You know how it goes. Any opinions?

 

[LSG]

Canted, what kind of exhaust sytem will this car be wearing ? what gears are in the toploader ?
I'm going to suggest something similar to an M code or Q code factory cam, something nice and wide on the LSA, like 114 or 116* wide. LSG

 

[supershifter2]

imo going with trick flow 195 wedge heads is a downgrade. I drag raced a friends 73 with a 4VC and i had 2 cars with 4VC engines and would never put a smaller head on a C. you dont need a big cam with a 4VC head to make great power to 6500. Around .550 lift is real good for that.

 

[stroker393]

“Edelbrock Air Gap intake, or Performer intake if the Air Gap won’t fit under the shaker”

This will fit,consider Ron Morris adjustable motor mounts.

 

[macstang]

Make sure you are giving the compression calculator the right intake valve closing degrees. They generally want that number at .050. Comp cams for some particular odd reason lists theirs at .006. One of the calculators I use will calculate the at .050 for you so for most relatively streetable cams it winds up being in the 30 something degrees at .050.

This one has the calculator specifically for Comp cams.

The static and dynamic compression ratio calculator

 

[Westmus]

imo going with trick flow 195 wedge heads is a downgrade.

I believe OP talks about the TF 195 Cleveland heads.They show how far head design knowledge have come since the 60s. They are based on the stock 2V design, but flow better than the much larger factory 4V heads

 

[hotrodfords]

“Edelbrock Air Gap intake, or Performer intake if the Air Gap won’t fit under the shaker”

This will fit,consider Ron Morris adjustable motor mounts.

View attachment 886864
View attachment 886865

That’s really a beautiful setup you have there.

 

[Hemikiller]

IMO, run the 62cc heads. I'm right at 10.5:1 with iron 4V CC heads on pump gas. My cam is a Howards roller, and calculates out to 8.1 DCR on the Wallace Racing calculator.

 

[CantedValve]

@Hemikiller That is the cam we are considering for the 62cc, except with 110 LSA. As ground it gives me 8.25:1 We are looking at a bit smaller cam (still Howards) with the 72cc heads that would need 4 degrees additional advance to get up to 8.0:1. 230245-10, which is what is in my Cleveland. Of course it goes to waste since the deck height is stock, pistons are stock, and the 2V heads dont really flow. It it replaced a wiped flat tappet cam, and I didn’t want to do that again.

@stroker393 is that what you did to make it fit? The adjustable mounts?

@supershifter2 sorry, I wasn’t being clear. There are 351C specific heads that Trick Flow makes. They flow 313 @ .600 lift.

The car will have a Flowmaster 2.5“ system, and I’m thinking right now FPA headers. Likely going to do a wide ratio Toploader.

 

[CantedValve]

Make sure you are giving the compression calculator the right intake valve closing degrees. They generally want that number at .050. Comp cams for some particular odd reason lists theirs at .006. One of the calculators I use will calculate the at .050 for you so for most relatively streetable cams it winds up being in the 30 something degrees at .050.

This one has the calculator specifically for Comp cams.

The static and dynamic compression ratio calculator

I’ve used that one, and what they do is add 15 degrees to the 0.050 number you provide. It’s an estimate for seat duration. I’ve read and thought about all the different ways to calculate it, and just chose to go with seat duration.

 

[wawazat]

Looks like stroker393 has a 1/2” or 3/4” carb spacer in the stack up too.

I’m following this one as I need to swap in Shaun’s old 393 stroker with RPM Air Gap to my ’69 Cougar without a hood scoop and I’m concerned about hood clearance. Stock motor mounts and Edelbrock standard dual plane fits now with 2” air cleaner and offset base.

 

[Hemikiller]

@Hemikiller That is the cam we are considering for the 62cc, except with 110 LSA. As ground it gives me 8.25:1 We are looking at a bit smaller cam (still Howards) with the 72cc heads that would need 4 degrees additional advance to get up to 8.0:1. 230245-10, which is what is in my Cleveland. Of course it goes to waste since the deck height is stock, pistons are stock, and the 2V heads dont really flow. It it replaced a wiped flat tappet cam, and I didn’t want to do that again.

The car will have a Flowmaster 2.5“ system, and I’m thinking right now FPA headers. Likely going to do a wide ratio Toploader.

I bought the 112LSA as it was the last one they had in stock, this was Dec '21. Builder advanced it 2° to give me a little extra low end. Very happy with how it runs, tractable down low and pulls like a freight train. Only pushed it to 5k so far as it's still a fresh build. Running a Torker, Holley 800DP, wide ratio toploader as well, but still have the interim 2.75 gears 'cuz I've been lazy AF this winter...

 

[stroker393]

“s that what you did to make it fit? The adjustable mounts?”

I was mostly concerned with header clearance. The set up is not true shaker but custom base plate to allow MSD clearance AND air gap. I still added a spacer (3/4) inch to set shaker height. To the best of my memory I used the adjustable motor mounts for side to side movement and the stock height.
I have FPA headers with TF 190’s,as a note the FPA headers have custom flanges to accommodate the 0.100 different exhaust height as per FPA.
Cam lift is 602/612 roller as per Ford Strokers.

 

[CantedValve]

That’s nice!

 

[CantedValve]

I have made a decision! Based on the fact that we are running the Trick Flow heads (a more modern design vs. stock with what should be a far better chamber, and made of aluminum), and the fact that Señor @Hemikiller is running (almost) the same cam in an ironhead version of the same motor, we are going to go with the 62cc heads and the 231175-10 camshaft that closes at 69 degrees for an effective compression of around 8.3:1 (I can retard it 2-4 degrees if needed to bring down effective compression). This is a 4 speed car with gears so it should work well.

 

[LSG]

Canted, I'm going to suggest a RETHINK. I believe thats more duration than you need or want, but if you can't get a 112* version, get a 114* or a 116* spread. Your engine will NOT act similar to HemiK's, the 110 is TOO TIGHT. LSG

 

[CantedValve]

The options are 110 or 112 LSA. The duration isn’t that radical. You mean it’s got too much overlap?

I’m basing it on an engine I found on YouTube today of a stock stroke Cleveland built with Edelbrock 60cc heads and a Comp Cams 32-600-8 camshaft. That camshaft has more duration than mine and a tighter LSA. They are largely building the same engine I am, except we chose slightly different heads and a different cam.

 

[LSG]

Canted, yes, thats exactly what I mean. The Clevelands do not need, and really do not even WANT the narrow LSA cams. Yeah, I know everyone sells them, and I know that the kids down at DQ think its really cool if your idle is so bucky/chuggy/raspy/gaspy that you can barely get through the parking lot. BUT the car will DRIVE BETTER with the wide. No, the choices are not 110 or 112. Call Howard's and tell them thats the lobes you want, BUT you want them on 116* LSA spread. Its all do-able. The idle will throb rather than gasp/chug. The driveability difference is like night vs day. 99% of camshafts are just chosen out of a catalog, by a guy reading some Chevy grinds off from a page. A guy who knows NOTHING about how Clevelands are quite different than others, and who has not built dozens of them, and had a chance to see what works well, and what does not. Don't let anyone tell you have to have 'scavenging'. Most of the street driven cars NEVER run high enough rpm to see it. Get a 9 key timing chain, so you can move the cam as needed. BTDT. LSG