I am currently building my 66 Galaxie. So I purchased a 79 Ranchero with a 460 and a c6 trans. I plan on building the engine for my 66. It currently has a 373 gear in the 9" rear. What kinda of hwy rpms should i expect with the c6 transmission? The reason for my question is because the set-up I had before was the 390 FE with the cruise-o-matic trans and same gear and it would top out at 75 mph @ 5500 rpm. Not very hwy friendly at all.