Hi guys. Got a 400 off of FB marketplace. Came out of a 1980 150 or 250. Not sure which. Person had disassembled it in preparation to rebuild it. He thought it was a 351m and when he saw it was a 400, he decided to go a different route. I got the complete engine and all the disassembled parts for $50.00. I want to rebuild it and put it in my 78 F250 eventually. I don't want a race engine. Good torque, good throttle response and reliability are what I'm looking for. Would like to do the usual. Get it hot tanked, measured, magnafluxed, etc etc. I'm open to getting different heads, valve springs/rockers, upgraded cam, straight up timing. Might be able to be talked into more as well. But just a typical refresh/rebuild for the most part. Also, anyone know of a good machine shop in or around Portland, Oregon? Thanks!

 

Thatsrealnice,

I'd suggest a roller cam before cylinder heads - for longevity. If you want aftermarket heads, a Trick Flow Power Port or Edelbrock Performer RPM would suite your build very well. Is your F250 a 4x4? Manual or automatic? Gears & tires? More details are helpful.

 

Sorry. Need to remember more info is always better. It is a 4x4 and a 4 speed. 4.10 gears and and 235/85/16 E load range. I put an Edelbrock Performer 400 manifold and a Holley 600cfm 4 barrel on it. I'd likely transfer the intake and carb to the rebuilt engine. I would like to put a ZF5 in it someday too. The engine is all disassembled now and would rather do everything while it is already apart.

 

There is a lot you can do on a 400. Cam and timing chain will make a big difference. A roller cam will ensure longevity and due to their lobe ramp design they usually produce more power across the entire RPM range. Aside from that a roller cam almost eliminates the chance of a flat cam lobe on break-in.

After the cam and chain the next big change is pistons. There are not a lot of options. Stock pistons have very low compression and are still sensitive to detonation due to the lack of piston to head quench. Tim Meyer offers pistons designed for the stock 400 heads. If you choose to go with aftermarket heads you are almost certainly stuck with custom pistons. For reference a 62cc head with 0 deck pistons require 30+cc’d of piston dish to keep the compression at 9.5:1. Some aftermarket heads are available with 72-74 but those still require special pistons.

Tim Meyer offers some special cam bearings that divert more oil where it’s needed and you may want to look into this. Some people say you don’t need it but I don’t know anyone who is upset with the results.

Your intake and carb will work well with this new motor.

 

I dropped the block off at the machine shop today. They are going to go through it, do their measurements and let me know which performance upgrades I might be interested in. I can't wait to see it when done. Been waiting years for this to happen. will then do the clutch and go through suspension. Probably get the steering gear rebuilt through Bluetop Steering.

 

Great find on the engine and good luck with the build. I’d like to stroke out my ‘80 351m.

 

The late model heads are that hot. Restrictions in the exhaust. Not the therm thingy.

 

Vastly better TMI pistons plus mild cam and timing chain will prolly give all the power you want...

https://www.tmeyerinc.com

https://www.summitracing.com/parts/sum-k5201

https://www.summitracing.com/parts/s...1r-9/make/ford