I recently removed the engine from my 1977 F-100. It's a 351M, I have already removed the intake. (S2P2 edelbrock) I was planning on replacing it. Any cam ideas would be great too. Also, should I switch to 4v? Thanks to all replies.

 

Bump? Any help?

 

I have zero knowledge of the 351/400 series engines but given it's a smog era Ford I'd be willing to bet it has a tiny cam in it so just about anything would be an upgrade.. like something with 250-260 advertised duration and maybe 0.450" total lift at the valve.

 

351m, cam is terrible. New cam and straight up timing, you will see an improvement. Small 4bbl, ok. The next major problem is low compression. There are no easily obtainable pistons to fix that. The "fix" is to make a 400 out of it with aftermarket pistons. All you need to know is here:

335 Series- 5.8/351M, 6.6/400, 351 Cleveland - Ford Truck Enthusiasts Forums

That is the 335 series forum, and just as in the FE forum, there is about a thread a week on how to make a 351m or 400 into a respectable engine.

Read through the threads, there are several recent threads that address your questions.

 

Do yourself a favor and put a 400 crank in it. If your going to rebuild it anyways you are going to bore it and will have to buy pistons anyways, the rods are the same. Get a hold of TMI on here for all your needs. The 351M's are such a low compression short stroked turd a cam isn't going to do much of any good anyways. Turning it into a 400 and getting the compression up where it belongs is your only option if you ever want to get anything out of a 335 series engine.