[C10 - C90 Bill]

Nice looking truck. If it has the standard, original rear gears they will be kind of low. It should do OK around 55 or 60 on the Hi-way. Not sure what kind of speed limits you have out there.

I was always satisfied with the stock Stromberg Carb. My '66 GMC 305 would get 15 1/2 miles per gallon on the Hi-way after a "super tune" just using stock Delco and AC parts. Although I have switched to Borg Warner Points in recent years.

If you decide to change the rear gears, remember it will mean starting off in 1st will be more of a strain. I would suggest to keep it original if you can keep it under 60 most of the time. You can change the ratio a little by putting extra large tires on the rear. My '72 C-10 had more of a problem with high revs on the Hi-way than my '66 GMC did and I put on a set of 265/75R/15's on it and it was enough to make a difference, plus I like the look. I'm running 235's in the front.

Keep us posted.

Bill