[SCOTI]

Originally Posted by kglowacky

here's what I know as I am not up to speed with all the details as all I did was buy the motor and trans out of a 2001 Camaro and install it, Then sent the pcm to cal. for them to fix the harness. The only thing I know is I did tell them the raer end was a 308 when in fact it is a 370. I never sent it back for them to re set it. I didn't think it would matter that much. The truck is all stock except for a 2 inch drop in front(spindles) and 4 inch in back(shackles and mounts). Tires are factory steel wheels and 235/75/R15. don't know rpms I dont have a tach

Your tire size w/a .70 OD gear should yield 2100 rpm @ 70mph. Thats where you need to be. Anything lower will drop highway rpm's but they're in range of the 'small block' sweet spot.

Simply lowering rpm's beyond the sweet spot doesn't gaurantee better mpg's. The efficiency of mass going down the road will have an impact (these trucks are kind of a brick). Vehicle specific tuning is a must for your quest.