396 L78 block

[EZ Nova]

Originally Posted by chris slawski

Hey folks-
Can a L78 4 bolt block 69 vintage accept an over bore to 4.250 for 427 displacement or will it become unstable?

asking for a friend

For the cost, WHY?? you could probably buy a ready to go 4.250 or 4.280 bore block for less?

Keep the L78 for L78 stuff or people.

IF your looking to go fast, the added bore will help some, but in the end is it really going to be worth it? I myself see no reason for this unless to mislead people or a class by claiming to be a L78/396 and be stroked? Like some sort of stock-block class.

FYI I did a mild 402 to 575Hp back in the 90's with mostly GM stuff. Used OEM L78 short block, Ported sq port closed chamber heads, strip dom intake and comp .660 solid roller. Ny '69 Nova would run 10.40's with 9" slick, thru muffler and 4.56 and M21. I'm sure with what we know now, I could put that deal in the high 9's or low low 10's, WITH A OEM "163" intake.

So tell us WHY your thinking this bore?

Thanks, John