400 big block

[sincere88]

hey guys its me again.has anyone ever heard of some dropping a 400 big block into a 88 caprice if so,whats the process like? thanks for your help Chevy Boyz!!

[silicon212]

Originally Posted by sincere88

hey guys its me again.has anyone ever heard of some dropping a 400 big block into a 88 caprice if so,whats the process like? thanks for your help Chevy Boyz!!

400 big block? What make? Although Chevrolet advertised one for the 1971 model year, it was really a 402 - and that in turn was a 396 factory overbored .030".

[broughy84]

there's not a 400 big block. There's a 366, 396, 402, 454, but not a 400. However there is a 400 small block, which would be the same outside specs as any other sbc.

[HLandin]

Correct, the 400-cid was a small block. Its basically a bored 383-cid. The major problem with the 400-cid was that the cylinders were siamesed, which caused the block and heads to overheat.

[Blue Bowtie]

The overheating potential is really overblown. It really doesn't happen that often, and there are easy things which can be done to minimize or eliminate any overheating problems. Surely, the potential for hot spots is slightly greater, but it's not as common as some would have you believe.

FWIW, if you perform the math, a "402" is actually 0.029" larger in bore (to make it a nice, round 4-1/8" bore) - Close enough.

Which do you really have? The 400 was only made for a few years, too, even though there are a lot of aftermarket siamesed bore blocks out there, and a ton of 406s and quite a few 426 SBCs on the street.

[silicon212]

Correct, most Chevrolet NASCAR engines are built with the 4.125" siamesed block (albeit one designed for the purpose). If these can run 500 miles WOT without overheating, the 400 should be able to have a managed cooling capability.

[1968 Pontiac]

I had two 73 Caprice ragtops which came with 400 small block's. Never had a problem with overheating. The only problem I had with both was baaaad gas mileage; about 10mpg which rivalled my 67 Lincoln Continental winter car I had at the time. With one of them I did however add headers, crower cam, aluminum intake, HEI, Holley 600 carb, shift kit, etc. and managed to boost the milage to 20mpg. The other one I pulled the 400 sbc for a 425hp 454. Mileage wasn't bad at 16mpg, but it sure was a lot more fun to drive!

['97ventureowner]

I rebuilt a 400 sb into a high performance 406 which made it into a few of my Chevys . I was aware of the potential for overheating especially with boring it out .030 . I installed a 4 core radiator and used a high flow, high performance cooling fan( 5 blade) with no problems.

[ilgoldstein]

I looked through a beautiful "coffee table" book on the SBC today at Borders. It indicated that the 400 SBC did not really put out much more HP than the 350 and got worse gas mileage. When it came out, Motor Trend panned it.

The book is a real nice item, has a lot of history on the development and deployment of the SBC through the years, although I caught some ommisions, and the info was sketchy at times. Lots of pics of great cars.

I go in from time to time and will get the author and title.

[silicon212]

Originally Posted by ilgoldstein

I looked through a beautiful "coffee table" book on the SBC today at Borders. It indicated that the 400 SBC did not really put out much more HP than the 350 and got worse gas mileage. When it came out, Motor Trend panned it.

The book is a real nice item, has a lot of history on the development and deployment of the SBC through the years, although I caught some ommisions, and the info was sketchy at times. Lots of pics of great cars.

I go in from time to time and will get the author and title.

The 400 was never a "Horsepower" motor - it was not designed to rev high with its 3.75" stroke and 4.125" bore. What it did, and did well, was pound the asphalt with gobs of low-end torque to spare. That's one reason why it was popular in some trucks until its discontinuance in 1980.

[1986Z28]

guy in my neighbourhood did it, actually pretty cool, btw guys he learned the point the first time its a 402 not a 400, no need to keep repeating it

[sincere88]

so the "400 big block" is actually a 402?am i right? is there a way to run a 402 or even a 454 i a 88 caprice?

where can i find a nice set of vogues from for cheap?

[capriceowns]

Originally Posted by HLandin

Correct, the 400-cid was a small block. Its basically a bored 383-cid.

no, the 383 isnt a block size. its a 350 with a longer stroke.

400 is actually a 389 pontiac engine bored over. or at least the original one was. idk much after that.

[1986Z28]

id say its a 402, because chevy never made a 400ci mtor other than a sb

[silicon212]

Originally Posted by blownalcoholboy

id say its a 402, because chevy never made a 400ci mtor other than a sb

In 1971, Chevrolet offered its 402 big block as a "400 big block" which is where the confusion comes in. You're right, there was never an official 400 big block, but Chevy did market one for one year.