Starting with a well seasoned 2 bolt main motor with iron heads.
(Out of 9C1 Caprice)

Assume the following:

Block is line honed, zero-decked and bored with torque plates.

Studs for the main caps.

Steel crank, H-beam rods and forged pistons.

Entire reciprocating assembly balanced.



Now, regardless of whether it's N/A, Blown, sprayed, whatever...

What is the practical limit on torque for a street driven motor that needs to have REASONABLE reliability and longevity.

(Meaning that I don't care if I have to rebuild it again at only 75-100k miles, but I damn sure do care if I have to at 25k.)