Hello everyone kinda new to the whole turbo thing been mashing around my twin turbo set up. I have had suggestions of twin 76mmor twin gt45 y2204, I keep looking at the s475 with 1.32 ar. I know they are big and heavy but they last and make good power from what I hear. I have been told they will be quite laggy. I would love some input.

1967 valiant back half 4 link
power-glide gear venders 180 straight cut
355 Dana 60 with spool
will use 29.5 10.5 w at track
going to have a ptc custom converter made
I have a a/a inter-cooler from chiseled
Motor will be a blow thru 451 with decent set of heads -1 or top end ez or sr
9.1 to 8.8 to 1 compression
cs carb with custom headers and cam to match set up

all input is welcome thanks