The problems were specifically related to MAC L/Ts (surprise) and several 4V engines boroscoped after using the MAC headers showed evidence of weld slag being introduced into the cylinders through the EGR system.
I'm thinking about getting the BBK Lt's. Will the BBK L/T's bolt up to a Bassani X or will I need to change the mid pipe? Also, how difficult is it to do yourself. Can it be done in a garage, do you need special tools?