sheppyfire87

i need to know if this motor i bought is really what he says it is. so this motor i was told is a 350 bored out to a 400 can this be done?if so how can i check to see if it is a 400 thanks, shep

Nsomnia

On a factory block it definitly can not be done. 360 is about as big as you want to go on a stock block (.060 over i beleive, since .030 is 355)

five7kid

iTrader: (14)

You can go to about 396 with a 3.8" stroke crank.

But, you can't bore a 350 block to 400.

Get the casting # off of the block. That's the only way to know what it is. Ditto the crank.

sheppyfire87

thanks guys! now i have to go break some legs!!!!

sjaak84

I read somewhere it is possible with a 4inch stroke cranck. then you get 401ci

//<86TA>\\

iTrader: (15)

ive got one, its a 408. I didnt build it, but making the cranks work is apparently a closely guarded secret of the company i had build the engine. More then just a little grinding.

Apeiron

It's not much of a secret, it's the same as making any other stroker crank fit.

sjaak84

for sure you need a small base circle cam for clearence. what kind of cranck you used??? Is it a cranck disignd for a 400 block and grinding down to 350 mains???

sheppyfire87

hey guys thanks for the info i called the guy and i guess i missed heard him he's telling me it is a small block 400 and not bored out from a 350 now how do i find out if it its a small block 400?

BluFBdy

iTrader: (1)

casting numbers

Darkshot

iTrader: (4)

Give us the casting numbers. Back of the block where the transmission bolts.

sheppyfire87

well the motor is in the car is it possible to get it with the motor in the car?

84 Z-28 350

you are going to have to use a mirror, the # are cast into the block on the drivers side just in front of where the transmission bolts up, they will tell you the year range, size of the engine, sometimes the car body and somtimes wheather it is a 4 bolt or 2 bolt main, this link may help http://www.ajgeneral.com/sbc_block_casting_numbers/

sofakingdom

iTrader: (1)

No a 350 cannot be "bored out to a 400". The blocks are made in a substantially different way.

It is possible to stroke a 350 out to about 400 inches; but this is VERY rarely done, and tends to be quite expensive and dificult and risky, and it is therefore HIGHLY unlikely that it is such a one.

As far as the block is concerned, either it IS a 400 block, or it IS NOT a 400 block. The casting number WILL tell you that, and it DOES NOT lie. If the number says it's a 400, then it's a 400. If the number says it's NOT a 400, then it's NOT a 400, and you can take it to the bank in either case. It is absolutely positively unequivocally CERTAIN identification, one way or the other.

The casting number won't tell you whether a block has 2- or 4-bolt main caps installed on it. The factory MAY have put either kind of caps on some block castings. However, all 400s in the first few years had 4-bolt caps, and all of them from about 73 up had 2-bolt caps on them.

Here's where the casting # is.



The block in the pic is, in fact, a 400 block.

There are only 3 400 casting numbers; 511 (early), 509 (the one in the pic is one of those), and 817. Any other casting #, it's not a 400.

The early blocks, roughly all 511s which also have 4-bolt main caps installed on them from the factory (although there are a few exceptions), had 3 freeze plugs in the side, instead of 2 like ALL other SBCs including the majority of the 509 and 817 castings. That makes those particular ones VERY easy to spot.

sheppyfire87

from what i can see i think it says 8970014 but i might have to double check that

KrisW

iTrader: (5)

3970014 (starts with a 3, not an 8) is your garden variety 350 from 69-79.

If that's what your number is...

sofakingdom

iTrader: (1)

Not a 400, if it ends in 014. Just yerbasic 70s 350 block.

I hope you didn't get gypped into paying 400 money for it?

Rule #1 of buying used cars (or used parts): NEVER EVER FOR ANY REASON believe so much as one single word out of the seller's mouth, unless you can verify it by some other means. (your own eyes)

Rule #2: In case what the seller says seems like it could be true, see Rule #1.

sheppyfire87

it runs pretty good and i only paid $400 for a completed motor so im not sweeting it but it still suck thinking i had a 400!!!!!!!!!!!!!!