Chevy small block 400 question.

My son and I just bought a small block Chevy 400 cu. in. engine for him to rebuild and install in his '79 El Camino. He's heard that .030 is the max. you can overbore this block. Haven't got the heads off yet and we don't know if it's standard bore or not. Anyone know if this .030 max. overbore information is true? Thanks for any help.

Garrett Fulton

Reply to
Garrett Fulton
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yes

the reason is that there is no water passage between the front and rear pairs of cylinders on each side

that's how they managed to get 400 inches out of it...........max bore + minimum metal

Reply to
TranSurgeon

Thanks. That's what I needed to know.

Garrett

Reply to
Garrett Fulton

Make sure your cooling system is rock solid. New radiator, flush the block etc. As was mentioned, no water passages, then if you start upping the HP you start making more heat, and these are not known as cool running motors.

Big Chris

Reply to
Big Chris

My son's going to have it boiled out, line honed and bored with torque plates. Already has a new radiator on the El Camino. He really wants to get everything done right. However, I can't understand why all the aftermarket overhaul kit suppliers that we can find only offer .030 oversize pistons. If .010 or .020 would clean it up after we get the heads off Monday, that's what he'd like to to.

Garrett

Reply to
Garrett Fulton

aftermarket

Reply to
sidewinder

Thanks for the input. We read this .030 max. overbore deal in a Chevy small block overhaul book and from a Car Craft article about Chevy small blocks. A couple fellows my son knows also told him this. I'd like to think it's not true. I do think the longer rods are a good idea, also. I'll check the Northernauto website.

Garrett

Reply to
Garrett Fulton

Reply to
sidewinder

TRW makes standard cast pistons in Std, 20, 30, 40, and 60 over. Part number

400NP. And, forged pistons in Std, 30, 40 and 60 over. Part number L-2376F.

They also have the rings for all those combinations, and about any other part you will need.

Al

Reply to
Big Al

Thanks Al.

Garrett

Reply to
Garrett Fulton

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