Well, for now the 350/350 combo will stay. But...My engine of choice when the cr looks the way I want is a 6-71 Supercharged 409. Not sure what I want for air cleaners yet though. Thinking just the small 4.5" with no bug catcher. Keep it with in the late '50s to early '60s theme. Plus I am trying to figure out if I want to build onto the frame or have my dad build a new one. Are these frames prone to twisting under stress?