what is the best small block and why ?

340 , have 2 now and they are stronger than the 2 360 (2 cranks waked) and 2 318( 1 crank went bad ,2 timing chains and cracked piston) I have had in the past . Better crank , better timing chain and gears , better pistons cam and heads . 360 and 318 cheaper ?? I don't see it .

When rebuilding from scratch? Sure, but it's only a few bucks more to do a 340 IF you allready have one. There often sold at a much higher price than a 360.

Sorry to hear of the past troubles. Something wasn't right. I have had no problems with ethier engine. Power level ceilings of a cast crank arent as high as a forged, but then again, how many people apporach that level on breaking a cast crank?

Proper parts for the proper power level to do the job properly. Reliabley for a long time.