Why is it so hard to find stuff for a 351cj, and why is it so hard to get a conversation going about these rare but great engines, it seems to me like they are the black sheep of the faimly and no one wants to do anything with them.I love mine but wish i could find out more about it.

 

Maybe the fact they are so rare is why their is nobody to talk to. I have only read some about them and most of the info is scarce and debatable. Their is little published info on these rare engines other that the fact they were produced. Maybe someone will chime in with a site that has what your looking for.

 

Im not saying you dont know your engine but are you sure you dont mean 351C (cleveland)? The "Cobra Jet" engines i know of that were produced were the 390CJ, 428CJ, 429CJ, and 429SuperCJ. Never even heard of the 351CJ and i have several different manuals and retoration book for the early mustangs and none of them mention a 351CJ. Not even the ones with special engine information mention them.

 

yes im sure i meant 351 cj, I know that it sounds weird but they did make them for about 4 years look at my photos and it shows the engine block code.

 

Ahhh, the infamous Q code. They didn't make many, so parts are gonna be rare if you need something Q code specific. If I had a Q code I'd feel bad about putting CHI heads on it.

But I would put CHI heads on it, and a roller cam etc. The bad feeling would go away once I had 500hp on tap.

 

I have the complete engine with all the origanal parts, but i am curious on what would be good for more performance on these wonderful engines that are better then the stock parts. The only thing thats i dont have origanal is the cam i had the origanal but it was worn out so when i rebuilt it i had comp cams special grind one out for me .I have bored it 30 over cause it needed it and got it decked along with the heads, also put a double roller on it, got it balanced and did the heads with stainless valves and brass guides along with a 3 angle valve job and ported and polished the hole engine to match up all intake and exhaust flow. Then i topped it off with a edey performer rpm cause the new air gap was made for the 2v not the 4v []. But dont worry i kept the stock intake lol. Last but not least i put a 750 edey thunder on it cause the holly just wouldnt seal right (strange hu). So any help about these engines and what would be better then stock for performance on this puppy would be great cause finding info on it is a pain in the ****.

 

Cylinder heads. As good as the cleveland heads were in the 60's and 70's, they suck by today's standard of performance. Badly.

Granted, they flow better than any other stock head for small blocks that Ford had, but the current aftermarket heads are lightyears beyond the older factory stuff. Some of the newer aftermarket heads are even significantly better than some of the factory heads in use right now.

For a Cleveland, one of the best heads to use would be CHI. They make a modern aluminum variant of the Cleveland head they call a 3V, has much smaller ports than the factory iron heads so the port velocity is higher, but they also flow considerably more, and make much more power in streetable rpm ranges than the factory heads can. You could get a 351 to put out 500+hp on pump fuel in a drivable rpm range with those heads.

Definately keep the stock heads though, at the very least they're worth money. And you may put them back on later if you decide to sell the car in original trim.

 

The right cleve heads do not suck, by any means.Factory289/302 headsare horrible, no two ways about it, but cleveland headsare in a league of their own. The 2V versions flowvery well in factory trim, and with some very mild porting and larger valves they'll be downright amazing. The 4V versions don't even really need to be ported, but you do have to build the engine around them and try to make power in a much higher rpm range.

No, they won't be quite as nice as the 3V CHI heads, but saying they suck is justplain wrong. Most people are perfectly happy with their factory cleveland heads. If I put that much money into having my cleve heads ported, I probably wouldn't bother with aftermarket heads.

 

thankyou to all who help with this information it does help, but does anyone know were i can find more information on the 351cj it self?

 

That's why I said they suck by today's standard of performance. Most modern head designs flow way better than even 4V heads, with much smaller ports so they have insanely higher velocity and make more power. They are a 35+ year old head after all, and technology has come a long way. Some modern heads that have a port size similar to a 4V head are flowing 100+cfm more. Pretty much any stock heads suck compared to many modern aftermarket heads, the only exception being some of the newer heads from the factory, like GM's LS series heads, or Fords newer 3V, which is ok, but by no means superb.

The modern standard for performance has become quite high. High enough that even most modern factory engines aren't able to meet it, with very few exceptions. Factory heads will work on the street, and can make resonable power. But if you have the money, and want something that's going to make power on a more modern performance leve, you'll need better heads. It comes down to how much performance you want and how much you're willing to pay to get there.