Best heads for 351M on a budget

Probably 2v Cleveland heads or maybe 4v if you get it breathing heavy enough. I'm not an expert on the 351M/400, though.

There are some people around here that know how to build them, but you'll probably need to do some detrective work to find them.

I did a little looking around and it does in fact seem like Cleveland heads are the most logical choice with cost as a consideration. You would have to find a special intake, though. It also appears that the 400 shares the same block as the 351M, so the 400 internals could be used for an extra 49 inches. I'v heard of the 351M/400s being great torque engines.

That or you could put a 460 in the truck. I think they have the same engine mounts and bellhousing.

best bet would be to use some aussie cleveland heads since they have the 2v ports. i'm not aware of any intake made for the 351m/400 other than the performer 400 unless e'brock has started making a performer rpm intake when i wasn't looking. it's going to be tough to get that much RWTQ from a 351m, i would also suggest replacing the crank and pistons with the 400 parts, the rods are the same so you shouldn't need to change those. check some of the ford truck forums for build ups on the 400 i've seen some pretty good ones on there.

You'll never get that kind of power with a 351M, Period. Do as the others suggest and swap in a 400 crank and pistons, but for the pistons, you need a custom set with a pin height that will put them up to the deck, not the usual .090 down the hole. If you don't use the right pistons, adding quench heads is pointless. Only heads for you are the stock 351M/400/351C 2 bbl heads.(The Aussie 2 bbl iron heads are a good choice too, but will cost you more) Only intakes are the aforementioned Edelbrock Performer or the Weiand dual plane ( P/N 8010 if I ain't mistaken) I built one such a couple years ago that made good power, but pinged like crazy with a 9.7 to 1 comp ratio. Power wasn't any better than a mild rebuilt 390 though. And 390's like lower octane gas to do it. All in all, you can build a healthier 460 that'll swap in the 351M's place for less money. The build I did was a good learning experience, but cost me $2000+ to do and I ended up with the same power a 390 could do for half the money.

as far as i am concerned, the 351m block is good for two things

1: building a 400

2: a boat anchor

i would prefer building a 400 myself. the stock heads are good to use with a little clean up of the ports, an edelbrock performer intake or the similar wieand intake are all you have to use, but they do the job. as for a cam the comp cams 268 does a good job. built right a 400 can make some decent power for little money, but the 351m isnt a good combination.