How Much HP / Boost Can a stock 420a lower end handle?

[DKSTREET1990]

I have a fullly built head and am now considering building the lower end of the motor. money has become tight and was wondering how much boost and hp stock pistons and rods could handle.

thanks

 

[dustyboner]

a low mileage engine will handle 8-9 psi for a little while as long as its tuned properly.
but
if your head is fully built, you might not wanna run boost on the stock bottom end. If you break a piston or rod, you could end up trashing it.

 

[DKSTREET1990]

Thank you, I agree and I have the mega squirt 2 for tuning. Just don’t want to destroy it

 

[BLACK'98DSM]

I've heard that 7 psi is what you can reliably run. The weak points in the bottom end are the ringlands.

I'd never boost or spray a 420a without it being built though.

 

[DKSTREET1990]

Thank you for helping me out and I have decided to go ahead and build the Lower end before installing motor again