Having run a blown small block street/strip since 1985 I'll put in my 2 cents. Mine is a 340 so not everything applies. Stock block was used over 20 years, no failure. Upgraded to a R-3 block a few years ago. The result is less blow by,the breathers never drip a drip now. Original stock crank, rods were from the Chrysler Trans Am program. Venolia forged piston( 5/64 moly rings). I have beat on this thing to 7000 rpm a long time. Carb's were very rich a one time,not now. Stock jetted Carter Comp 750's, A?F is still 11.8-1 at wot. Timing is the key. Destroyed 2 sets of pistons before I figured that out. Only30 degress total lead. Same pistons since 1991. I run 12 PSI. Car runs 11.0@123 3875lbs in street trim.
Doug