318 Mopar vs. 340 Mopar
The 340's are getting very pricey to come by and to build. Remember they haven't been in production since '73.
If you're doing a street car, the 340 pistons are nearly impossible to find at any compression less than 10 to 1 or higher. We looked for 3 months or more just to find new forged 8.5 comp pistons for our 340 Demon. We wanted street use w/ pump gas.
I like the 360 idea as others have suggested. 2nd choice would be the 318
Just my opinion.....good luck w/ the build. :cheers: