[Trav]

well gona build a motor.. persoanly i like the 350 sbc.. but i like to be a little different one someone asks wut u got under the hood.. but im just curios if there a good motor for a starting point? i no they were slugs in the old trans ams..?? but is there a way to build one with lotsa balls?? im looking for around 400hp with no blower or nitrous.. and are the blocks pretty common? im putting it in a 1979 full size chevy.. so i want some power to move it.. wut cars/ trucks did the 400 come in? are they built for tourqe or hp? im not very familiar with 400's. thanx for any info

[DoubleVision]

the 400 small block chevy came in trucks and big cars like station wagons from 70 to 76, 77 - 80 they were mostly in trucks alone. some also came in vans. the 400 is a torque engine, not a high revver, they have a 5.565 rod compared to all the other small blocks 5.703 rod. the bores are siamesed or made together, the engineers had to do this to fit 4.125 bores in a block only meant for 4 inch bores, they have a larger main bearing size of 2.650 compared to other small blocks 2.450. they are also exteranally balenced, meaning the balencer and flexplate must be used as a set, if you used a 350 balencer or flexplate on a 400 it destroy`s the thrust on the bearings. the siamesed cylinders caused them to have steam holes between the cylinders, and the heads and head gaskets must have these holes otherwise it`ll overheat. 400 sbc never came in trans ams, they came with a 400 pontiac or a oldsmobile 403. with the right heads, compression, cam, induction system, and headers, a 400 will eat any other small block up. only catch is you can`t rev a 400 like you can the other small blocks without it coming unglued.

[Trav]

ok i think i got it man.. ya pontaics.. sorry i thought it was trans ams.. my bad.. o ya it came in the 400 gto's right... now those motors got balls! anyways.. ya i need tourqe in my big truck.. so no reving then right? just like big blocks? i had a 454.. over revved it a couple times and learned the hard way.. i'v also read about the steam holes thanx.. dam they didn't make them very long at all did they?? from the sounds of it this is the motor i want! its just a matter of find me a block! thanx for all the info.

just curios.. if anyone know's the average horepower rating of 400's? stock of course.

[74Ventura]

According to the book I've got sitting here the 1970 400sbc in the monte made 265bhp@4400

[HemmiGremmie]

Get you a 350 crank, 350 rods and make it a Destroked 377. Quickest reving engine there is and tons of power. HG

[Trav]

ya i also read on the internet that the 69 GTO's had 355 with the 4 barrel.. so i guess i gota look for the right block... but who know's wut the casting #'s should look like.. a destroker eh? that doesnt sound to bad either..

[crash70rs]

do a 350 crank and a 5.7 inch rod to make it a 406, strong motor.
but the like to run a little hot unless you open the coolant passages in the head gasket.
my moms car hs it, it run consistant low 12's all day without any tunning and traction problems

[drewhelm]

GTOs ONLY came with Pontiac motors in them. Pontiac did not make big Block or Small block motors. GTOs may have come with 355 gears in the rear end, but NEVER a 355 Pontiac motor. The Pontiac 350 and 400 crank is IDENTICAL. Same stroke, same journal sizes, etc. So if you put a 350 crank in standard bore 400 you get a 400. Pontiac made up cubic inches between the 350 and 400 with bore size.

Pontiac motors are definitely torque monsters. You could build an inexpensive 400 to make 400 hp and plenty of torque for your truck very easily.

[Trav]

sorry about that drewhelm your right.. but wut i meant was the pontaic 400 had 355 Horse Power.. i'd love to get my hands on one of those motors.. and ya i new that they never had the big or small blocks.. all the same.. also they had a 455 did't they? in the judge? or somthin around those #'s.. but it would be nice to find one of those motors.. i'v seen those cars go.. no a buddy with a couple of em.. should get ahold of him! so tell me this.. how come pontiac stopped making there own motors?? or did they?? cuz in my 01 Trans am it's the LS1 thats in all chevys sports cars.. i think it would bin more exotic if they had the 400 in it.. but anyways.
wut #'s do i look for on a block to see if its a pontaic or chevy?

[hotrodhill]

I have a 77 chevy truck with a 406 small block, 400 .030 over. I have towed my race car many miles and the truck is my daily driver, I love this combo, my opinion, thanks, Tom.

[SSedan64]

Nooooo another 5yr old thread.

[Double_v23]

And to think I took the time to read through it...

Which was pretty painful considering the grammer of the original poster.

[dawg]

build a 406 (best bet out there)
I built mine with longer rods and forged crank.
dynoed @570 hp
who says you cant rev a 400 block?
of course you can if you use the right parts.