what is the best small block and why ?

$500 for a complete 340?

HOLY SNIKES! WHY are you still here chatting it up, go get that sucker. I have been seeing blocks sell for $700 and there in deep need of machine work and degreaseing in a big big way!!!!!!!!

IIRC, not a 100% on this, but I do believe that a 72 is a lower compresion year. The heads are a letter head series and may, MAY have the 2.02 valve. It could be a 1.88..

Reguardless, the 1.88 can be opened up to a 2.02 and then ported the same as a 2.02 head to the same level as any other letter head.