Aside from the manifold bolt mounting differences, is there a significant difference in chambers, valves, flow characteristics between a 94 TBI head and a newer Vortech head, assuming both came off their corresponding 5.7L year model engines?

I'm planning on rebuilding my 94 5.7L TBI into a 383 Suburban tow motor with EMPFI from Edlebrock or Accel and am wondering if a head change would be warranted. I know I could go all out on some AFR's, but...

I intend to maintain the stock RPM range and am looking for cost effective low RPM torque.

Any recommendations on this project would be appreciated.

Thanks!!