I found a deal on a 351/400M engine and C6 trans out of a 77 F250. I know very little about this model engine other than it has an integrated timing housing and that the bellhousing pattern is the same as the 460 BB. I have an early 302 with a C4 that needs to be gone through but if this 351/400M is a good alternative then I'll go with that setup instead for my 54 F100. Thanks...

 

I'd love to swap my 302/C4 for a 400M/C6.. Especially since my 302 is from 1972... lowest horse power of any 302 V8 ever. lol

 

53fatfndr and danlee(335 series forum) both have done it in their trucks. Mines a '48 so my frame's 2" narrower, but Hoof has fit his into his '49 (?) If it's a 400, I'd say you got a good torquey engine. The 351M was smogged to oblivion, and that 302 probably makes just as much hp. fwiw, the 351M/400 is more similar to the 351C. A simple "straight-up" timing set in that motor will wake it up. cams, intakes, exhaust(Sanderson are most likely what you'll need) and such can be read to no end in the 335 series forum. You may come away impressed how underrated these engines are.

 

DITTO - had a 351M (Modified 351 with 400 heads) in my 1979 Ford 1/2ton and it was a total DAWG. Swapped it out for a 460 and had nutt'in but fun. Darn good thing we had 1000gal fuel tank back on the farm.

 

I should add that 1971 specs on the 400 is the best. and the only difference between a 351M and 400 is the crank and pistons. even the connecting rods are the same.

 

Good engines with the Smog Crap removed.

I got an article from Hot Rod, Sept 98. "The 400 Ford: 468 ft-lb, 380 HP for less than $2,000

Send me a PM with your email address, I'll send it out.

Oh It's 351M/400 Engines. The M after the 400 is a no-no, something has to go in the Pickle Slicer for useing it.

 

Go for it! They are a under rated engine. Some guys get some nice numbers from these engines.

I did the opposite of you. I dropped a 302/AOD in place of the 400/C-6 in my 78 f-250 frame. It bolted right in.

 

Years ago I stuffed the 400 into a 1959 Ranchero. I had more than enough power for the truck and got fairly decent mileage. It wasn't a race care but it did all right.
I imagine that an engine from 77 is going to be "smogged to oblivion" though.

Good luck
Bobby

 

a 351 M they make great boat anchors!! I worked at a Ford garage years ago, and we changed crankshafts by the dozens.We used to call them 351 Mexio's someone said the cranks were made there?All I know is they had a weak bottom end in them.A 400 is a good engine with all the hippy tree hugger junk removed!

 

The 400 is a good engine for pulling. The four square bore produces a lot of torque and with the C-6 tranny you can tune it up for reasonable mileage. If I weren't working on a 410 FE I would opt for the 400. Good luck.

Gear Up

 

I looked it up in Tom Monroe's How to Rebuild Ford V8 Engines. On page 27 he says that the engine was cast at one of two foundries; the Cleveland Foundry or the Michigan Casting Center. Those cast at the MCC prior to March 2, 1977 experienced water jacket cracking problems immediately above the lifter bores due to an internal coring problem. The cracks will be horizontal and approximately one inch above the top of the lifter bores. Look for the casting date code. The magic date is March 01, 1977 or 7C01 . These codes are located on the top-rear of the block next to the oil pressure sending unit hole.

I know from past experience that those engines were a departure for Ford and they are neither fish nor fowl. Whatever speed parts are available for them are meager, and pricey.

 

ive talked about it before , but i had a 400 with cleveland 4 v heads a set of weisco domed pistons { c.r. was like 11:1 or a lil higher } i cant remember where i got the rods and a nasty roller cam , and i beleive a victor jr or torker intake with spacers from rousch to bolt it on { intake was cleveland and not wide enuff for the 400 } and a holley . it was in one of my sportsman cars a maverick !! , dirt track obviously and that thing gave the s.b.c crowd fits !~!!!!!!!!!!!! it's only drawback was the weight it deposited on the nose of the car . don't ask about all the gory details as this was 20 plus ago . these engines are ,have been and probably always will be underrated . big bonus they are cheap as no one has a clue !

 

Charlie

Here's what I'd do.
Tear it down and clean it up, check the info just given above by Dffay.
Clean up the crank as needed, get an RV Cam for it with new lifters and springs. Get a non-smog #%! Cleveland Dual Plane manifold, you'll need a set of spacers to make it fit the 400 Heads.
Get a good 4bbl carb thats made for electronic ign. Get a programable electronic ign that has been pre set for your eng/running gear. A good set of headers, and a good torgue converter for the C6 and You'll be a Man About Town.
This combo will give you the torgue and power that you need and set in a light Truck the gas milage should not kill you.

 

Thanks for all the good info. The reason I am even considering this engine/trans combo is because it seemed like a good alternative to rebuilding the 69 302/C4 setup that I already own. From everything I've heard it sounds like I'd be just as well off tearing into the pre-smog 302 and building that engine as buying the 351M/400 and essentially doing the same amount of work on it. Once again, thanks for all the info...it's nice to have so many brains to pick!

 

As the saying goes, try and build what you have first before swapping. Seems to apply even now. I'll take that motor if it's a 400, though.