340+ for the STREET

hemisedan said
Those are as close as I can come to numbers. I've seen crate 402 or 408 motors with 420 hp, which would probably work. But, I still don't like cast cranks and that is what they usually use with the lower power motors.

Ok, this is why we ask. To go low 13's in a A-body doesn't take near 400 ponies, even with highway gears. The number 1 horsepower number thrown out there, be it a chivy, ferd or mopar guy, it's always 400 hp. It is very easy to get one horsepower per cubic inch in a mild built street motor. I think 340 horsepower would be more than sufficient to achieve low 13's, keeping highway gears and spread bore for the mpg, and be very reliable.

Start with a good exhaust (Doug headers, backed by a good system)
Followed by good heads-factory 340 heads will fill the bill if you do the following: hardened seats, good valve job, mildly ported. HEADS are KEY.
You could find a better cam, but the factory one works well with the two mods listed above.
IF automatic, get a good converter.

Your well on your way (not sure much more is needed).... and I'll let others chime in. Options are plentiful, such as overdrive tranny, FI, and a big list that will follow I'm sure.