Vintage Mustang Forums banner

which build

  • Clevor 408

    Votes: 6 26.1%
  • 408w

    Votes: 17 73.9%

  • Total voters
    23
  • Poll closed .
1 - 20 of 37 Posts

·
Registered
Joined
·
303 Posts
Discussion Starter #1
Looking for a little advice on my next motor build for my 67. I currently have a 90's truck block 351w, I also have a set of eagle H beam 6.25 rods with chevy journal sizes.

I want a 408 bottom end for torque. Trying to decide if I want to do a clevor or a windsor.

I have a set of 71 or 72 (cant remember) cleveland 4v open chamber heads in good shape. They would be treated to once piece valves and hardened seats etc as well as a spring pack that compliments whatever cam ends up in it.

My other option was a set of RHS 225 heads as they seem to be a decent budget head that will support a 408w

Car is a street car, 100%. It might see a strip once a year, but HAS to be a pump gas (91 octane) build. 93 is available here, but not everywhere and I want to do cruises etc.

Looking for stump pulling torque and a "fast" street car.

car is an automatic and currently has a 2400 stall, but could change if needed. And this summer its getting an 8.8 with 3.27 gears, but would consider 3.55's if it was optimal.

It may see some interstate time, but primarily just primary and secondary roads at around 55-60 mph

I also like the "cool" factor of a clevor and supposedly those 4v heads will support more hp than I will end up making.

Shooting for an honest 400+hp, but if more is easy and still streetable, more is always better right?
 

·
Premium Member
Joined
·
10,814 Posts
The W block has a way better oiling system and oils the mains first. the 9.5 deck of the W will give a better rod to stroke ratio. i have owned 3-351C 4V engines , a 351W , and i currently have 2-392W strokers. the W is the way to go.
 

·
Banned
Joined
·
2,711 Posts
I too agree that a 351w based stroker motor would be a better choice. I had a 351c with 4bbl heads in a 1968 fastback and it was great for punching it on the freeway at high speeds but my buddies who had stockish 351w's in a 67 coupe and 69 cougar would beat me every time. The Cleveland also was not a favorite of mine. I had it rebuilt and it ran great for a few months and then it started not running so well again. My current engine is a 351w, bored .030 over, aluminum heads and it puts out 450hp/tq at the flywheel and stomps on both of their cars. It's relatively easy to get 400hp out of a standard, non bore 351w and a 408 or 427w would be even easier with numbers more likely to be in the 500-600hp level
 

·
Registered
Joined
·
10,025 Posts
Unlike most people, I'm a big fan of the 351 Cleveland. Back in the day, when good aluminum heads weren't available, a Clevor was the way to go.

But now there are many good choices for 351W aluminum heads. Considering the hassles of building a clevor, like finding the right intake and machining everything to make the Cleveland heads mate up to the Windsor block, things would be much easier just getting good aluminum heads for the 351W.

Now, if for any reason you want to stay with iron heads, you won't find any better iron heads than Cleveland heads. Since your Cleveland heads have open chambers, you'd have to deck the block and mill those heads to achiever 10:1 static compression which is what Cleveland heads really need.

All the stuff you hear about Cleveland heads being too big for the street, that the heads are inefficient, etc. is complete bunk. The Cleveland is the most misunderstood American V8 ever. Anyone willing to overcome the myths, and a few genuine issues, with a Cleveland will be rewarded with a mind-blowingly powerful engine.
 

·
Registered
Joined
·
10,025 Posts
I had a 351c with 4bbl heads in a 1968 fastback and it was great for punching it on the freeway at high speeds but my buddies who had stockish 351w's in a 67 coupe and 69 cougar would beat me every time.
I'm sorry to hear that. There was something seriously wrong with your Cleveland. A well-tuned 351 Cleveland will run circles around a 351W. In fact, it will smoke, or at least keep up with, the big blocks.
 

·
Registered
Joined
·
303 Posts
Discussion Starter #8
wont have to mill or deck anything, going stroker bottom end with a windsor block and choosing heads. I think some of you are misreading the in initial post.

Either combo will be on a windsor bottom end to avoid the cleveland bottom end pitfalls

I understand the work it would take to match cleveland heads to and intake and windsor block, thats one of the downsides, but the port size on cleveland heads is huge and flows a ton, and with a 408 bottom end I should be able to use it properly. Comparable windsor heads cost alot

C302b heads would be great, but pricey.....
 

·
Premium Member
Joined
·
11,511 Posts
I'd think long and hard about using open chamber C heads. Back in the 70's the C fanatics avoided the open chamber heads like the plague. They just didn't make power like the closed chamber heads. It would be worth your trouble to investigate the current thinking on open vs. closed heads.
 

·
Incorporated Sell Out
Joined
·
17,130 Posts
So I have a 408c using stock 4v OC heads and a 408w using AFR 205s..........I'm still getting to know the 408w (it only has a few miles on it)....they are both nice and will both put you back in the seat in a hurry
 

·
Registered
Joined
·
303 Posts
Discussion Starter #11
I'd think long and hard about using open chamber C heads. Back in the 70's the C fanatics avoided the open chamber heads like the plague. They just didn't make power like the closed chamber heads. It would be worth your trouble to investigate the current thinking on open vs. closed heads.
I called a couple reputable C builders. Closed chamber is better, but for strret and average compression ratios open chamber has a better flow
 

·
Registered
Joined
·
303 Posts
Discussion Starter #12
So I have a 408c using stock 4v OC heads and a 408w using AFR 205s..........I'm still getting to know the 408w (it only has a few miles on it)....they are both nice and will both put you back in the seat in a hurry
can you tell me more about your combo with the c heads? PM me if you want
 

·
Premium Member
Joined
·
10,814 Posts
I too agree that a 351w based stroker motor would be a better choice. I had a 351c with 4bbl heads in a 1968 fastback and it was great for punching it on the freeway at high speeds but my buddies who had stockish 351w's in a 67 coupe and 69 cougar would beat me every time.
something was wrong with your C. The 73C 4V CJ i put in my 66 would blow windsors away, sb chevys away, 455 trans ams away, and a few ss 396 chevys away. 340 mopars and a few 383's got eaten to. and that was with the skinny 70 series tires on the back. i left them in a cloud of tire smoke it was awful for them especially the non smokers. cough cough. i look like a dam geek ! how could that have happened ?!
 

Attachments

·
Incorporated Sell Out
Joined
·
17,130 Posts
Forged crank, h bean rods, 10.5:1 custom cam in the 63/64 split duration lift range, solid lifters, screw in studs, roller rockers, full cleveland not a clevor....runs/makes power to 7500. Runs so far (with idle start) 11.2....expecting 10s next trip out thanks to a new AOD trans from lentech. Runs down the highway as a commuter occasionally without issues.
 

·
Premium Member
Joined
·
10,814 Posts
I called a couple reputable C builders. Closed chamber is better, but for strret and average compression ratios open chamber has a better flow
you can run higher compression with closed chamber before detonation. open chambers will detonate sooner. boss 302 heads are a little better.
 

·
Registered
Joined
·
10,025 Posts
wont have to mill or deck anything, going stroker bottom end with a windsor block and choosing heads. I think some of you are misreading the in initial post.
He posted his Cleveland heads have open combustion chambers. Therefore, to get 10:1 static compression with flattop pistons, he would have to deck the block and mill those heads.
 

·
Registered
Joined
·
10,025 Posts
I called a couple reputable C builders. Closed chamber is better, but for strret and average compression ratios open chamber has a better flow
I can't figure out why anyone would say that. Open chambered Cleveland heads result in lower compression, but there's no way they flow better than closed chambered heads. The 4V heads flow better than the 2V heads. Perhaps that's what they were talking about?
 

·
Banned
Joined
·
2,711 Posts
I had a 351c with 4bbl heads in a 1968 fastback and it was great for punching it on the freeway at high speeds but my buddies who had stockish 351w's in a 67 coupe and 69 cougar would beat me every time.
I'm sorry to hear that. There was something seriously wrong with your Cleveland. A well-tuned 351 Cleveland will run circles around a 351W. In fact, it will smoke, or at least keep up with, the big blocks.
To clarify, I would always beat them from a roll at 30-50mph or whatnot but stoplight racing I would always lose. It was frustrating because I had a toploader 4spd with a 9" posi rear end and 3.50 gears.
 

·
Registered
Joined
·
10,025 Posts
you can run higher compression with closed chamber before detonation. open chambers will detonate sooner. boss 302 heads are a little better.
The detonation issues with open chambered heads apply to wedge heads, but not Cleveland heads. Cleveland heads are not wedge heads. They are "polyangle" and have many of the benefits of a hemi.

The '69 Boss 302 heads had bigger valves, but otherwise, they were just Cleveland 4V heads bolted onto a 302. Any Cleveland 4V head will flow more than adequately.
 

·
Registered
Joined
·
10,025 Posts
To clarify, I would always beat them from a roll at 30-50mph or whatnot but stoplight racing I would always lose. It was frustrating because I had a toploader 4spd with a 9" posi rear end and 3.50 gears.
Yeah, that is one trait of 4V Clevelands. They're not torque monsters at lower RPMs. With a 4.30 gear, you likely would have left them in the dust!
 
1 - 20 of 37 Posts
Top