ok this might take a min. i have two trucks at the moment to deal w/. a 79 1 ton w/ 400 and a 78 w/ 300. the ton is dads and the 78 is mine. dad wants my 300 in his ton (it has AC by the way...odd option in our area) and i want the 400. so even swap but i gotta do all the work! no biggie. so i build custom trucks...they are usually what people call "lowriders" but really they arent. they are called minitrucks, lowrider is a generic term. so i wanna build a full size now. but not lowered too much (like a 5 or 6 inch drop, not too drastic). bigger rims (like 20's, no bigger) but i want the truck to have that hot rod feel. basically i wanna be able to smoke the tires in all 4 gears or at least 3 of em. and be able to blow away the local 5.0's and bowties (or at least keep up). so what i should have said is, what can i do to build a high torque and fairly high hp 400? i have read in the forum and noticed that many people say to use aussie heads? and rattle off all kinds of numbers to do w/ cams and valves and what not. ok i think...think i want the 400 to have high compression? that means flat top pistons right? not sure what is best. and can i stroke it a little or is it pretty well a long enough stroke? i know that they were build for torque, or at least thats what i have read. it wont be a daily driver, just another show and weekend truck. i have driven the ton that the 400 is currently in and it seems to only have power at low RPM. but then again i know the rear end ratio has a lot to do w/ that (not sure what the ratio is...i read there were only 2 options for that truck i think 411 and a 5 somethin). im also not sure what ratio the 78 has. it was a 300 automatic, im thinking probably high 3 somethin. i would have to check but i dont know how other than to jack it up make two marks and spin the wheel. and easier way?

Im not much of a motor man. suspension and body work are my things. However, i am trying to learn about engine specs and what would be a good motor to build. Im just a little confused at all the numbers. any help woould be appriciated. thanks

 

you will also have to swap trannies. the 400 i would skip and look for a 460. you will have to make custom a/c brackets for the 300.

 

i think i may have misled you a little. dad is keeping his 4 speed and i already have a 4 speed i have had for a while that Im going to mate to the 400. and for the AC, i know its the same compressor for each motor but different brackets. and thats no big deal to make new brackets. the only thing is that i have to let the AC go w/ the 300, but thats no biggie. 2 60 air doesnt bother me (thats 2 windows down at 60 mph) and i thought about droppin in a 460, but the 400 is free and i want it just because its an oddball motor. So far at all the local (Louisville,KY and Indianapolis, IN area) car shows i've been to, i have only seen very few 400s.

 

ok so then instead of complete tranny swaps you need to swap the bell housings. the 400 won't bolt up to a 300 bellhousing or the other way around. you don't see to many 400's because no one wants one.

 

[QUOTE=you don't see to many 400's because no one wants one.[/QUOTE]

all the better for those who know their potential. I'd do a 400 over a 460- any day. I'd also do a fe (390) over a 460 as well. 460 isn't special at all unless you want to waste tires after an expensive conversion and build. 400 is a great low end motor when built right.

 

also, the 400 has the longest stroke of a stock ford motor- can be built to major porportions and is a unique motor- once you say 460- people simply say ok and go their merry way- a stroked cleveland required a little more attention. And yes, you go another 1/4" on the stroke- see tmeyers site (sponser) he's building one- I think the stroked 400 may be competetive with all but the 7k plus builds on a 460.

I also am under the impression that a 400 is a better motor when built for low end and will get decent mileage while delivering far more than a stock 460.

 

ok another quickquestion. i know that the 351M has a crank w. a shorter throw than the 400. and i know that the 351M pistons are taller than the 400. and that they both use the same rods. so here's my question. can i put 351M pistons in a 400 or will ther not be enough clearance? i think i will keep the factory heads for now (lack of funds while at college) and just have them cleaned up and maybe ported and polished? you tell me. and install an intake. i have heard you can slap on an intake for a cleveland w/ a spacer. i know that there arent many intakes out there for a 400. but there are a few so maybe i am better off w/ one for a 400 and not the cleveland? again, you tell me.

roger dowty, i hear you on keeping the 400. i am fond of the 400's and not the 460's. i like oddball things and i have hear great things can come from the 400 as long as its done right.

i know that my 400 has very low oil psi when warm, and still not so good when cold. when i rebuild the motor little by little over the winter, i will have the crank ground/polished (whatever it is that they do) and have fitted bearings and seals b/c the just buying standard ones are not a good idea and will cause low oil psi.

Oh, and ford390gashog, i know that the bell housings are different. i have several SB (lack of better word at the moment) and only one for a BB (again lack of better word). so swapping the bellhousings is not a big deal.

 

ok i got this from a ford inspired article...

ok, so if the first 400s had 10.2:1 compression, if i buy pistons for the first year can i get that compresion ratio? and second, ford retarded the timing by 6 degrees, can i advanve it by 6 degrees? or will it run hot?

 

a little more of what i found...

Quote:

Several unique parts were developed for truck M-blocks, including flywheels for manual transmissions, harmonic balancers, and truck-specific intake and exhaust manifolds. The original “non-retarded” crankshaft timing gear was also re-introduced on truck engines

The 351C and 400 pistons have the same compression height (wrist pin to top of piston), but the M-block wrist pin is slightly larger than the 351C wrist pin.

The 351M piston is unique, with a taller compression height than 351C and 400 pistons, and it is not interchangeable with any other engine.

so does that mean that the 79 truck 400 is not retared by 6 degrees (that its not retarded at all?). and about the pistons, i guess the 351M and 400 don't interchange?

 

umm ok, i guess i'll just have to figure it out on my own then? yeah, thought so

 

the engine is retarded at the cam by 6 degrees. the 351m and 400 use the same pistons.

 

the first 400 in 1971 had 9.0 compression 1972 to 1982 had 8.0

 

the 351m and the 400 dont use the same pistons

 

i know that they dont use the same pistons, i was just wondering if i could swap out the two or not...i am taking it that i cant. and ron_29_1973, im not so sure those compression ratios are right. i have read from many manuals and web sites about the specs on 400s. not all say the same, but are close. and i know that it had high compression when ot first came out b/c it wouldnt run very well on pump gas so ford decreased the compression ratio. but it was a high 9 or even 10.

 

You can use the 351M pistons in the 400 as long as you also use a 351M crankshaft.