Hey All,
I'm rebuilding this 351m for my '79 f-250 supercab 4x4. I'm almost done. I sent the heads in to have a head job done and I got a call back. Apperently both heads were cracked between each of the valves, so I found a set off of a '77 f-150 with the same engine. I took those in and I got a call back yesterday and only one of those heads are any good. So I'm back on the hunt. I think I can use the heads off any 351m from 1977-82 right? my question then is there any smog ports or anything I would have to plug or change to match my factory ones to pass California smog? I did a seach and found this to https://www.ford-trucks.com/forums/7...s-on-351m.html

So I can use heads off of a 351c? how will my performance change? I pull more trailers and grades than anything with this truck. Thanks

 

351m and 400 heads are the same. Nix the 351c heads, probably don't have the smog fittings you need.

 

Instead of the Cleveland heads, maybe an aftermarket set would be in order? Granted, they're new and more expensive, but from what I understand, Edelbrock now makes heads for the 335 engine family, so that's an option. Myself, I went with Cylinder Head Innovations (CHI) out of Australia, but I kinda went nuts with my build, so it might not be a practical choice for you.

Another direction to consider is a pair of iron Australian 302 heads, which should breathe considerably better than the stock 351M heads. The only vendor I know of for these (and I'm sure there are more), is Tim Meyer at TMeyer, Inc. He's the man when it comes to the 335 engine family, and can give you good advice about what directions are available to you. I don't know what he sells those heads for, but I believe he reconditions them for sale.

As for smog issues, the only state I can think of that might give you a problem with that is California, which does pose a potential problem for you. Even Washington State, which is almost as bad as California, drops the emissions requirements after the vehicle is over 25 years of age. Anyway, just wanted to give you a couple of options.

 

Thanks guys! I thought this lovely CA smog would limit my options. If I can't find another un-cracked head I may consider new Thanks