73 351 cj heads

Hi. Well I am back with more questions for you all.

I was wondering if anyone had an opinion on a set of 1973 351cleveland cj heads as an improvement over the 2v 73 heads I have now? I've found a set with the intake for 50 bucks. The heads need to be rebuilt the guy says so what kind of money does that usually run ? My 351 is bone stock and has 60 k miles on it. Would changing the heads be a bad idea without doing an overhaul of the bottom end? Would the heads be a complete waste since I don't plan on changing the cam?

Sorry for all the questions. I just saw these heads and saw an opportunity if it would work.

Any help is very appreciated.

Taylor

I think the heads came with two different size intake valves. The bigger of them are 2.19 and I think the smaller is like 2.04. I ,for that price, would buy them. I think some had adjustable rockers also.

Ok if they are CJ heads (I think ford dropped the CJ designation in 1973) but they will have the larger 4v intake and exhaust ports. This means you will need to swap out your intake and exhaust manifolds as well.

If the pedestals are milled or flat then you will need adjustable rockers (not much benefit to this if your cam hyd)

If the combustion chambers are 'open' then you won't get much in the way of extra compression from them and some think that the open chamber design on the 4v heads tends to have pre-detenation issues.

So here is my two cents.

If they are open chamber 4v heads I would pass.

If they are closed chamber 4v heads and don't have the pedestals milled I would pick them up. $50 is a good price

If they are closed chamber 4v heads and have the pedestals milled I might pick them up depending on what my overall plan for the motor is.

Since you don't plan on swapping out the cam these heads may not help your current motor. What cam do you have?

Manifolds alone are well worth it, without the heads, as long as they're not cracked (common).

I'd buy 'em for the fiddy, even though I would never see me using them.

Yes, "rebuild" is a very, very loose term. You can "rebuild" for under a hundred, or some have been known to get suckered into spending a grand or more for a street cruiser.

Regardless of which head combo they are, I would never reuse stock Ford valves or springs in any Cleveland, ever. The often tragic reasons are well documented.

As far as an improvement over a stock 2V engine arrangement, it's my opinion that the swap wouldn't be worth the price of gaskets. The engine will require other changes in order to see any functional improvement.

Manifolds are worth it without the heads as long as they're not cracked (common).

I'd buy 'em for the fiddy, even though I would never see me using them.

Yes, "rebuild" is a very, very loose term. You can "rebuild" for under a hundred, or some have been known to get suckered into spending a grand or more.

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Not sure but think he was talking intake manifold not exhaust manifolds

Manifolds are worth it without the heads as long as they're not cracked (common).

I'd buy 'em for the fiddy, even though I would never see me using them.

Yes, "rebuild" is a very, very loose term. You can "rebuild" for under a hundred, or some have been known to get suckered into spending a grand or more.

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Not sure but think he was talking intake manifold not exhaust manifolds

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Ooops, yes, sorry, my fault.

(I'd still scoop 'em though

Ooops, yes, sorry, my fault.

(I'd still scoop 'em though

LOL me too

oh, didn't see they come with the intake. For 50 bucks that's not a bad deal.

And motoarts is right, new valves and keepers for sure if they are currently stock.

Thanks everyone for the replies. I'm still not sure what I'm going to do. The exhaust manifolds were cracked he said so I would need to get a set of those or some headers I suppose.

As for the cam I have it is what ever ford put in back 73.

Thanks everyone again for information. Even if I don't get them I've learned a lot.

Thanks

Taylor

If you want more punch. these heads might not help you. the 4 v heads are huge. You get more low end torque out of the 2v heads with a mild cam. but if you decide to cam up then those heads might be useful. But you would still be better off with aftermarket heads since head technology has evolved so much from the 70"s. I had my 4v heads completely rebuilt. and for pretty close to the same money I could of bought a set of edelbrock heads with everything on them. As said earlier you will need to change all the valves and springs for sure. If someone has a cj car that doesn't have the right heads it would be worth it. If I was to do it over again {and I just might in a few years. it's funny how you get used to more hp pretty quickly hahaha} I would go with after market heads.

just my 2 cents

nothing wrong with open chamberd 4v heads...specialy now days...back in the days of flat top pistons..it was very importaint...but now days...pistons are mostly domed or machined too make up for the missing space....so dont let open chambered scare you...specialy in a 4v..the smallest 4v valve i beleive is 2.08...which is still bigger than most big block chev's.....the biggest is 2.19 or boss 2.21...been doing alot of research on 4v heads..sence im going threw my motor....i have 4v heads...and i was told by jegs open chambered 4v heads are able to flow up too 800 horses!! with the right shims..springs and cam ..piston set up.....there ford guy said they took them on dyno over 800hp...he loved them..lol..im never going to push mine that far..but dont let open chamber scare you now days..thats old school

2v are great for street..long as you dont want over 400 horses..then you mite have to step up into another set of heads...any 4v head is able too out flow just about any head on the street..open or closed.

Thanks everyone for the replies. I'm still not sure what I'm going to do. The exhaust manifolds were cracked he said so I would need to get a set of those or some headers I suppose.

As for the cam I have it is what ever ford put in back 73.

Thanks everyone again for information. Even if I don't get them I've learned a lot.

Thanks

Taylor

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Hey for fifty bucks if you dont want them I will take them, They can set in the corner with my others.

If they are 73 heads they have the big 4v ports and the 2v valve sizes (2.06" intake & 1.655" exhaust).

All the '73 351CJ heads I have seen have had the 2.190" (I) and the 1.710" (E) valves. It is my understanding that the '74 351C 4V heads have the 2.041" (I) and 1.654" (E) valves.

The 4V heads have been touted as being excellent for higher RPM operations when the relative changes are made to the motors. Back in the day, my modified '73 351CJ was absolutely great from 3500 to 7500 RPM. In my experience, the 2V heads are much better for lower (around town) speed (RPM) driving - - read that torque.

That having been said, I have picked up a couple open chambered 4V sets at the local 2nd hand speed shop for around a $100 a set and consider myself ahead of the game .

In my opinion, it comes down to the intended usage and how much you are willing to spend. Any version of the Cleveland heads can be made to perform very well (indeed) with the appropriate amount of preparation.

BT