Quote:
Originally Posted by 66birdman
I guess I must be lucky or something. I have a 66 C15 with a completely stock 351E, SM420 and Dana 60 with either 4.11s or 4.56s (havent dug that far into it yet) and I get around 14mpg cruising at 55ish. Not sure what my RPMs are since I dont have a tach but I did put slightly oversized tires (235/85/R16) on it to make it capible of highway speeds. Side note the vintage salvage yard here where I live has a 4 speed with an aftermarket overdrive still attached to a 65 GMC if anybody wants me to go ask about it. I dont remember if the tranny was a SM420 or a SM465 though.
|
Be careful I have a stock 351E with the Dana 60 and 4.10 gears I installed a tach to make sure I am not hitting redline on the freeway and I am at 3100RPM at about 45mph with 33" tires