I have a very good set of Gen 1s that I have used for several years. Titanium valves have 16 passes since new, T&D rockers 1.9 intake, 1.8 exaust, CFE intake will take 2doms,or electronic fuel infection. ,also bungs for 2 n2o kits. $13,500. You may call me at 317-445-2663
The only difference is 1 hole is moved in rocker stand, and are more user friendly out of the box. Huntsville engines has a set, and a boat guy in Cali has to sets (DSC) ford guy. I can assure you these are top quality. 638 made 1380 on motor w Jeff Prock.
Blue Thunder is out of cores.