I just put on a set of Trickflow ported heads on my 383 Lt1. The heads have 215cc runners and flow 315cfm. I have a 52mm throttle body on it now, shouldI upgrade or is it still good?

 

A 58mm may do you some good on that beast.

 

I don't think you'll see a huge gain, but w/ heads that big a 58 won't hurt nothin'.

 

depends on if your going wild or mild. How big is the cam you sticking in there? How much work is going to be done to the intake? You may want to consider a monoblade by AS&M. Or you may be totally fine with the 52, it all depends on a number of factors.