early 340s were positive deck, meaning the piston comes up out of the bore. If yours do also, you better have them calculate the compression ratio. Most "street" strokers will have dished pistons to get down to a comfortable pump gas ratio.
I didn't know that about the 340. The higher compression is fine with me as far as race fuel and stuff I'm trying to build more of a drag motor than a street motor. Not to say I won't drive it on the street of course, but if I have to add 5 gallons of race fuell to it each time I fill up no big deal.