340 Engine Shake

Your engine/driveline set up has alot to offer for some real street performance.
Remind me what compression ratio?
Cranking cylinder pressue?
What size rear tire?

The current tire size is just under 26" 245/45/17. I think 25.6?

I don't know exact compression, but I calculated it to about 9.6 - 9.8 with the Lunati cam I had and this calculator. Deck Clearance Calculator | UEM Pistons