sgr

Can someone tell me, or point me to a webpage that lists what the ('90-'92) HP425 specs were? I'm wondering what was in that engine as far as heads, crank, pistons, rods, etc. A link to some photos would be usefull as well.

Thanks,
Steve

Cord

iTrader: (2)

I believe the engine was based off the old 420 or the 365 mag. That would have gotten you a stock GM rotating assembly. Forged crank, stock rods, rectangular port heads, forged pistons, etc. I believe that you were basically looking at the LS-6 engine with lower compression and less cam.

I take it that you meant 525 right?

sgr

Actually, no. I meant the HP425 that was produced, I believe, between '90 and '92, that was a 454. I can't seem to find much information on that engine.

Thanks,
Steve

Pat McPherson

I believe the same as a 420.
A 425 is a Gen V vs. 420 Gen IV.
Same as a 454mag with a much larger Crane cam and roller rockers...