Just bought some 351 heads from a mate, for my 351 rebuild. They've been reco'd and are nice and dandy, and I took some pictures of them with my "stock" 351 heads - the ones I ripped off the engine being rebuilt.
The only thing they appear to have in common is:
- they're both Cleveland heads
Other than that, they're are a few differences that I can see. First up, the new heads don't have ANY Ford casting numbers on them. They have casting numbers, but are nothing like my heads. No Ford logos at all. I guess Ford could've changed castings, but still...
But here's why I'm stumped. Head on the left (chamber1) is my stock 351 head. Original and untouched and bloody filthy. On the right, the new 351 head (chamber2). As you can see - quite a difference. Does anyone know what I've got?
They look like 302 cleveland heads, the chambers are quench type (closed), if the port sizes are the same between both heads you've got 302c heads, probably better for a performance build up because of the increased compression ratio, although it will be too high on a 351 for unleaded, they will need to be opened up a bit to work.
As 4Vman says, they look like closed chamber heads and will give higher compression causing pinging even on 98 PULP. Even more so if they have been shaved.
I would be getting them cc'd to determine compression ratio before they got anywhere near the top of my motor.
IMO you would be better getting you open chamber heads reco'd with hardened seats so you don't have to worry about lead additive.
__________________
The cop said "Do you know why I pulled you over". I said " Well, that all depends on how long you have been following me!"
My first thought was that they were 302 closed heads, but they're not. At least, they look only similar to closed 302 heads that I've seen. They're somewhere in between, if you see what I mean.
Have another look at the right hand picture - the actual "lip" of the chamber isn't round, but it's not the same shape as a 302 one. Around the inside of the lip, it tapers gradually in to the centre where the valves are...
Here's another angle... and they came off a street 351 running flat-tops, so I don't think they'll be too high a compression. But I don't mind running premium unleaded. And the reason I bought these is because they cost me less than a 1/3 of what I would've spent on getting my 351 heads done up...
My first thought was that they were 302 closed heads, but they're not. At least, they look only similar to closed 302 heads that I've seen. They're somewhere in between, if you see what I mean.
Have another look at the right hand picture - the actual "lip" of the chamber isn't round, but it's not the same shape as a 302 one. Around the inside of the lip, it tapers gradually in to the centre where the valves are...
Here's another angle... and they came off a street 351 running flat-tops, so I don't think they'll be too high a compression. But I don't mind running premium unleaded. And the reason I bought these is because they cost me less than a 1/3 of what I would've spent on getting my 351 heads done up...
Thats a better piccy. They are definately 302 closed chamber heads. Look like they have 4V valves fitted.
On my 351 even running 98 with lead additive (which reduces pinging) they pinged their heads off (pardon the pun) although I suspect mine had been shaved quite a bit. I think the cam profile can affect pinging depending on overlap - others on here will know more than me about that.
The other thing to look at is the rocker gear holes. Are the same size as your old heads and have the pedastals where the rockers mount been ground down. Make sure this is still the same as yours or you will be up for new rocker gear
I would still get them measured to work out the compression ratio.
__________________
The cop said "Do you know why I pulled you over". I said " Well, that all depends on how long you have been following me!"
Have another look at the right hand picture - the actual "lip" of the chamber isn't round, but it's not the same shape as a 302 one. Around the inside of the lip, it tapers gradually in to the centre where the valves are...
I think that machining "de-shrouds" the valves, allowing better flow in and out of the chambers. Especially if the are bigger than standard size.
Neek, you should have a casting number on the underside of the runner like brenx. I just checked my closed and open chambers and they both have numbers there.
Closed chamber has ARD1AE
Open chamber has ARD0AE
Yours will have the top number.
edit; I can see a casting number on your second picture. What does it read?
__________________
10.70 @ 125.00 on the black fun top
408 Cube Cleveland.
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.
Linear Mode
