Very very nice finds.

I was told the 454 in my car came out of a 1983 4 speed GMC one ton Dually farm truck, imagine it would have been similar when new. The engine code is LE8 and the 4 speed Muncie was standard with the one ton 454 and the gear bender he mentions optional. Ratings varied slightly by year from 1973 -1991 but generally hovered around 230 Net HP (330 Gross HP) and 365 foot-pounds of torque.

They did not disclose the Blazer engine however the 350 V8 was the only 8 cylinder offered in 1974 either a 2 bbl or 4 bbl. The 4 speed was the standard transmission with the 350 4bbl. This was good for 160 net HP (225 Gross HP) and 245 foot-pounds of torque.