I just purchased a 1977 F-150 with a 351M that is already out of the truck and in need of a rebuild. The previous owner had already purchased a crane cam, and I am aware that I still need to buy the aftermarket timing chain and gears. I would like to get some more compression but was wondering which would be the best route. I am on a budget of around 1200 bucks for parts and machining costs. Is there a way to use 351C pistons in my 351M? I would just buy 400 pistons from TMeyer Inc. but I have no 400 crank. Suggestions? Thanks.

 

351c pistons won't work in a 351m.

The compression height of a 351c piston is 1.63-1.635, vs. the 1.921 height for the 351m. So you'll really be down the hole with those.

They will work in a 400 as the 400 piston is the same compression height as the 351c.

Someone was talking Chrysler 340 pistons (iirc), but they show a CH of 1.824, so I don't see how that would work.

Source:

Silv-O-Lite - Better Pistons Since 1922

Maybe you can find some 4.030 pistons with the right CH and a pin that could be bushed to fit the 351m rod.

Or, just bite the bullet and go with the proven set up.

Keep looking for a 400 is what I'd do.

Good luck with it.

 

X2 on that. The 351M has NO after market pistons. Go with the 400 crank. Check your auto supply houses, they will either have one or know where to get one. That is the only way you're going to get a higher compression ratio cheaply.Then you can go with TMI opistons or the bushed 351C pistons. That's just my opinion. John

 

x2 on using a 400.

 

crank isn't a lot of money but I do remember the budget. tim meyer is the way to go. If using the cleveland route you buy pistons and extra expense of con rod work. either is good but in the end I believe the tim meyer route is cheaper in the end with the most results/compression. I just did a cleveland piston but I stepped into a deal at a machine shop because the customer bailed on the machine shop and they just wanted to break even on parts. still had to deck the block and line hone block also but in the end very happy with my project. catch you later!

 

just did a compression run on the keith black compression calculator. your gonna be around 9.6 compression with your setup. might be a little much for your appliction. I had to run a little thicker head gskt which is more expense. figured around 76cc head volume and keith black piston volume is 3cc and 4.100 head gskt bore. and normal thkness head gskt is .041. Not sure on you cam intake valve opening, mine is .033 and add 15degrees for your dynamic compression. If you want to run 88 octane gonna need lower compression. see ya!

 

I have decided to go with the stock pistons and a crane cam...not sure of the lift yet....edelbrock performer 400 intake and motorcraft 4 barrel carb...any suggestions on a distributor?

 

what distributor should I get to eliminate ford's ignition box?

 

I'd stay with the stock ignition. They are reliable and you can buy parts at any parts store if something ever goes wrong. Spend your money on getting the block align honed and as close to zero decked as possible. I'd also get the rods redone as well, then balance it. Find a 400 crank. Even if you have to buy one. The kits with bearings aren't all that much money.

 

Here's the latest:

Block has been bored .030 over, crank polished, rods resized, new pistons, heads resurfaced, new valves and valve guides, new rocker arms, new push rods, new lifters, new melling timing gear and chain, new melling oil pump, all new bearings and seals, new comp cam with .477 lift, new edelbrock performer 400 intake, and still yet to buy carb and distributor. I'm thinking I'm going to stick with a remanufactured stock distributor and a remanufactured ford 4-barrel carb of some sort. Bottom end is together and heads are on...will only be a matter of time before motor is in the truck!