Mileage versus rpm's

[cayoterun]

Originally Posted by kikkegek

over here propane is less then half price of gasoline, so I dont really care about lossing 10% power and mileage..hahaha...

I was just curious why mi highway and city driving are equal in mileage. I guess my rpm's are killing mee..

Wow! With that much difference in price it makes it well worth using propane. Another added advantage of propane is there's very little carbon buildup in engine as well as less emmisions out the exhaust.
It used to be that way here, but no more on cost savings.

City/hiway being the same, I don't have a clue on the 350.
We've used several 454s as work trucks, and the mileage always seemed the same on them, too. I think you could haul them on a trailer and they'd not get over 8-10mpg, regardless.

Good luck on your gearing.
Cayoterun

[Corts60]

Originally Posted by tucsonjwt

Gear vendor advertises 20% improvement in fuel economy. I went from 9 city to 11 city mpg when I started using mine. I don't know if GV alone would account for 22 mpg - that is like 100% improvement in fuel economy.

I think you missed where I said my truck is a diesel, which already by itself gets better mileage than almost all small blocks in these square bodies.

[Edahall]

Nobody has mentioned re-gearing the rear end to 3.08. Some of the Dodge D250's from 88-93 had rear ends with this ratio.

[kikkegek]

found somebody that is selling a th700r4 from a 87 K5 with a NP208 and axles.

will that fit my Suburban? what will I need?

[nekkidhillbilly]

you really just need the trans if im not mistaken maybeye the 208 but the axles you have will work may have to have driveshafts modded but thats it.

[Edahall]

Keep your 3/4 ton axles. TH700R4 would be OK and you would gain a lock up converter but somewhat weaker than the TH400 in your truck.

[wilkin250r]

Originally Posted by Edahall

Nobody has mentioned re-gearing the rear end to 3.08.

I'm nobody?