F unit engine replacement?

I have read that the Burlington Northern executive F-units were rebuilt to "GP38-2 Specifications" but I am unclear as to whether they had their as built 567 blocks with 645 power assemblies added or if they had "new" 16-645 engines installed

One additional limitation is the main generator. If it is rated for 1750hp, then it wouldn't matter if you souped up the prime mover.

Chain driven Roots blower? I believe you will find that they were gear driven. Some of the earliest GP-20s went to the WP, (D-Day on the Western Pacific, Virgil Staff-) and EMD had to experiment with the gear ratio to get things just right. If I recall my reading correctly, EMD replaced, under warranty, 60 turbochargers in the first year, on a fleet of ten units. (FWIW, Baldwins had chain driven camshafts-) Also, I was not aware that 567s were used on subs.

This situation has happened. Beside the Australian application, look at the FL9AC. EMD 710, access traction motors, in a modified FL9 car body.