351 CLEVELAND MODS QUESTION?

I have a 72 h.o. cleveland with same intake. I'm interested in the same.

I understand and have heard that the Aussie heads are the way to go on street engines now a days. I still like my '70 351C w/ 10.5:1 comp. and a CJ cam. Probably about 370 hp right there.

swap to the 4V quench heads(with stainless valves), add headers, a cam similar to the Boss 351 grind, 650 double pumper, and a good single plane intake. You should exceed 375 hp by a few. Good luck.

If you want a lot of performance, like approximately 470-490 FWHP, take a look at my sig below. It is a pretty standard route for a street /strip set-up for clevelands.

375 FWHP can be achieved with either 2v or 4v heads. I've had both and prefer the 4v, unless it is a lower performace daily driver. They are both good heads I just believe that the 4v's offer more potential and can still be very torquey, and will blow by a comparable 2v engine in the higher RPM ranges.

Therefore, my recommendation is the following: 750 CFM carb minimum, anything less is silly unless you want better gas mileage and lower power. Blue Thunder intake manifold if you want the Carb under the hood and great all around power - it is a lot like the Performer RPM for the 302's. For a perfomance cam, probably best not to follow the Boss 351 route, modern cams are much better. Also, solid cams are preferable over hydraulic cams for performance, something in the mid 230 range should allow great performance but be very streetable. There are good hydraulic grinds also if you want to go the non-adjustable route, but either way I would work with someone that can grind you a custom cam for a cleveland. Roller vs. non-roller cams is really a pocket book issue. Compression should be around 10.5:1, clevelands like compression and the quench chamber 4v heads are very tolerant of premium fuel. I run 93 octane fuel and run 10.75:1 compression and a cam that has a 112 lobe seperation angle and no problems. That is about it (basically). Make sure to get an electronic ignition if you don't have one.
A good carb, intake, 4v heads, and performance cam should yield you closer to 425 FWHP than a 375 FWHP motor. The 4v cleveland motors make great power easily because of the cylinder heads and they are a joy to drive.

I'd call a machine shop and talk to them, they'll give you some ideas.

And listen to 69Stang. He is the Godfather of 351C performance

UNVMATT said:

Thanks
I just picked up a set of 4V quench heads that are bare.
They have already been machined for screw in studs and "set up for adjustable valve train"..Can you help me with a parts list to get them assembled?

Click to expand...

Great, getting the 4v adjustable valve train heads is a definite upgrade. You'll want to get roller rockers. Are you thinking solid cam? Roller?

Well, you'll want to get a set of Manley one piece stainless steel valves with undercut stems and have a good three angle valve job done. New hardened seats and bronze valve guide inserts should be installed also. In terms of the rest of the hardware it should be matched to the cam spec's. The cam you pick will dictate the springs you need. Spend a little extra money and get 10 degree locks and retainers, and get the titatnium pieces. They definitely help the engine rev better.

This might be out of the budget, but if you can swing it have the bowls in the heads ported, and the chambers polished. With the 3 angle valve job a little porting will help the low lift numbers which is usually the Achilles heel of a cleveland. Go to the best cylinder head/machine shop to get your work done.

Is this a fun or cruising car, or is this your main transportation??

Only thing I would add....don't port the intake side with the 4v...just port the exhaust side. One thing the 4v's don't lack is intake flow.

dodgestang said:

Only thing I would add....don't port the intake side with the 4v...just port the exhaust side. One thing the 4v's don't lack is intake flow.

Click to expand...

Exactly. That's why I said port the bowls and polish the chambers. I had my intake ports "stuffed", it actually reduced the port volume from ~240cc'c to 225cc's. Some would argue that the bottom part of the exhaust runner inside the head should be opened up, where it appears to "pinch" the exiting flow of the exhaust charge. Also, the top part of the exhaust port or "roof" some say should be raised for a more direct exit. Some of the other cleveland afficianados have seen or used the old aluminum exhaust plates where you cut off approximately 3/4" off the exhaust port surface and attach a "high port" plate. I guess it adds a lot of horsepower but requires custom headers. Not exactly what the weekend street cruiser needs or wants to do but I guess could be worth up to 80 horsepower in the right application.

[QUOTE='69Stang]Great, getting the 4v adjustable valve train heads is a definite upgrade. You'll want to get roller rockers. Are you thinking solid cam? Roller?

Well, you'll want to get a set of Manley one piece stainless steel valves with undercut stems and have a good three angle valve job done. New hardened seats and bronze valve guide inserts should be installed also. In terms of the rest of the hardware it should be matched to the cam spec's. The cam you pick will dictate the springs you need. Spend a little extra money and get 10 degree locks and retainers, and get the titatnium pieces. They definitely help the engine rev better.

This might be out of the budget, but if you can swing it have the bowls in the heads ported, and the chambers polished. With the 3 angle valve job a little porting will help the low lift numbers which is usually the Achilles heel of a cleveland. Go to the best cylinder head/machine shop to get your work done.

Is this a fun or cruising car, or is this your main transportation??[/QUOTE]

How much should I expect to spend on parts/machine work to add to a bare set of cast iron heads? One possible parts list I saw in a post recently...

CompCams Magnum Steel Roller Tip Rockers ($149.88)
CompCams Competition Cams Valve Springs ($86.88)
CompCams Magnum Pushrods ($102.69)
CompCams Pushrod Guideplates ($46.39)
CompCams Magnum 7/16 in Rocker Studs ($45.39)
CompCams Steel Valve Spring Retainers ($59.99)
CompCams Valve Locks ($24.88)
Cam & Lifters: ($199.00) CompCams Magnum 280 Hydraulic Cam and High Energy Hydraulic Lifters

Then Machine shop services
Magnaflux or pressure test?
how much to machine for screw-in studs and guide plates?
how much for hardened seats?
Valve job?
New guides?
Porting?
Polish bowl?

Could anyone fill in prices and add/subtract from this list? I'd like to have a comparison between buying some used cast iron heads versus aftermarket offerings. Also to learn how much a complete set of heads are worth versus bare.

I do not think there is a cost efficient aftermarket replacement head for the 351c.

And whatever you do, do NOT use the 280H. step upto a 292 or bigger. A 280H is too small behind a 351c, power cuts out way too early. When we ran a bigger cam, the car drove just as good, but pulled much stronger/higher.

mach1one said:

I do not think there is a cost efficient aftermarket replacement head for the 351c.

And whatever you do, do NOT use the 280H. step upto a 292 or bigger. A 280H is too small behind a 351c, power cuts out way too early. When we ran a bigger cam, the car drove just as good, but pulled much stronger/higher.

Click to expand...

Those parts were from a 2V build. Which brings up a good point - don't assume that what works for a 2V will work for a 4V or vice versa.

Whether the replacements are cost efficient depends on the machine shop costs for working with iron heads, the relative weight and the relative performance. I'm thinking the cost difference between iron and aftermarket might not be much if you get a lot of machine work done on the iron heads. Also depends on what you originally pay for the iron heads.

"Could anyone fill in prices and add/subtract from this list? I'd like to have a comparison between buying some used cast iron heads versus aftermarket offerings. Also to learn how much a complete set of heads are worth versus bare. "

You forgot the valves......I would go with Manley stainless steel valves and their products. Also, I would spring for the titanium hardware, an extra $100 but well worth it for the extra rev's. I think that getting a bare set of heads is the way to go because then you can build them up to your spec's. However, if you can find a complete set that has been upgraded with screw in studs and guide plates you might be able to save a lot of money. If you find a deal on a used set you should still take then in to a reputable cylinder head shop and have them checked to make sure the guides, seats, valves, etc. are in good enough shape to be used safely. Nothing worse than dropping a valve at 6000+ RPM's

There are aftermarket heads now - CHI and AFD - but they aren't that cheap and the CHI heads require their intake which is very tall, similar to the Parker Funnelweb intake. My understanding is that the AFD's will accept a standard cleveland intake with some massaging. Edelbrock is reputed to becoming out with an aftermarket head for the cleveland, also.

I found this information online

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I just completed set of 4V CC heads with Ferrea stainless steel valves, screw-in studs
and guideplates and dual coil springs for a solid flat tappet camshaft up to .680" lift.

$225.00 Bare stock heads (matched set off of an M-code Mustang)
$135.00 Ferrea S/S valves (2.19/1.71)
$100.00 Crane dual coil springs/retainers/single groove locks
$560.00 Machine for screw-in studs, 5-angle valve job, hardened exhaust seats, high
performance seals, bowls blended, cleaned/painted/assembled
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$1020.00

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I've seen heads go for a lot more than $225 on ebay. The poster had the machine work done in Phoenix, AZ. His price list doesn't include porting - I guess he did it himself or just left the ports alone. Aluminum heads don't look that bad to me in comparison. Hmmm.

"Aluminum heads don't look that bad to me in comparison. Hmmm. "

Yea I have over $2000 in my quench 4v heads, it is eqsy to spend a lot of money - of course they perform incredibly. The only problem I see with the aftermarket aluminum heads are the intake manifolds, otherwise they are a great alternative. With the CHI heads you are really limited to using their intake which is very tall and won't fit under the hood of any classic Mustang.

I run the Parker Funnelweb intake and I had to cut a hole in my hood and the air cleaner barely fits underneath the non-functional shaker hood scoop on my 1969 fastback. I have heard the AFD heads match up with most cleveland intakes pretty well, but I would still take it to a machine shop and have them matched perfectly. No sense in having great heads and then having a port mismatch with the intake manifold! If I were to go aluminum I would research the AFD heads. Hopefully, Edelbrock comes out with a great product that is user friendly.