1973 340 budget build.

trigger_andy said
Thanks again. :D

Heres the .20 KB Pistons I found earlier. Do you think they are the same as the ones you spotted at .30 over?
Keith Black KB Performance Pistons SKB243L-020

Yes

I mentioned to Michael just now that the builder had a set of oem forged .20 pistons for me, but Im not getting them now. :( So Im hoping I can user the KB ones in my link above? Any idea of the CR Id get with them?

There are on line calculators to figure this out. Try Wallaceracing.com, you'll need head gasket information as well as where the piston sits in the cylinder. Zero deck or the amount above/below the deck.

I might have a new damper, I'll check, if not it looks in very good condition. Its a 340 'cast' Damper anyway. Are these as likely to explode with age?

They don't explode, they separate. The rubber between the two rings rots away.

I guess I should start porting the Heads now then whilst I save for the correct Pistons.

Port the heads after the valve job and valve size is selected.