i need some engine advice

Muscleman, your 340 has a "340" can. Just like every other 340 has. You just have minor diferances between your engine and the earlier ones. They would be a cast crank, less compresion and a smaller intake valve. That is where it ends. That's it.

Follow what 72bluNblu said with ol'kimmers distributors advice.
Moper has an excellent tip as well.
Honorable mention to JOHNNY MOPAR for that video and Huges whiplash cam suggestion.
Huges has a good idea with that cam for lower compresion engines to help build up cylinder pressure.

Sedanman, that guy who said "A low comp 340 is a glorifed 318" needs to be shot! LOL. If he wants anything inthe future, I'd charge him double for spite. LMAO!