HELP, Seeking the forum's members input for their own experience

[boreguard]

I'm looking at a 1981 3/4 ton 2 wd truck. It has a 350 w/what sounds like a RV cam (noticable but not radical) a new Holley 650 CFM and aftermarket intake. It has a TH400 automatic and 4.10 gear ratio.

The fellow that has it hasn't had it ( he's actually a mechanic here close to home) long he got in a swap of some other things. He has no clue as to MPG but suggested that it would probably come in somewhere around 12 to 15 MPG depending on cruising speed and etc. The guy has an excellent reputation, but I don't know him personally.

I just wanted to see what other members with similar drive train combinations experience in the way of MPG.

Thanks
Dennis Neal

[Captkaos]

on a 3/4T, I wouldn't expect 15mpg, 12 maybe. 

[ccz145a]

I would agree with the 12 figure, but then, you don't get these truck for the mileage now, do you.

If you can live with 15, you can live with 12 or even 11.

[78ScottsdaleK20]

I have a 1978 3/4 Ton 4x4 with a 4" lift sittin on 35" tires. Motor is a mildly modified 355 mated to a SM465 4 spd hooked to a NP205. 4.10 gears. Truck weighs 5,200 + lbs.

When running good I can see 10 mpg, 12 if I stay out of it. Highway miles dont improve much maybe between 12-15, depending on speed. I cruise at 3,000 RPM at 60-62 MPH.

Maybe this helps, maybe it doesnt. This biggest difference between mine and yours is weight and 4x4. So you should see a little better depending on your drivetrain and condition of engine.

[monte85]

i've got a 87 3/4 ton with a 350, q-jet carb, turbo 400, and 4.10 gears. my motor has a gm performance parts 383 truck cam(a noticable idle but not "lumpy") and my average is 12 mpg. this seems to be the magic number.

[boreguard]

I appreciate the input, and yea I understand the logic of saying that you don't buy a 3/4 ton for gas...but it's good to know what is a reasonable expectation vs. ignoring it all together and finding out that it's only good for 3.5 mpg after the fact and then raising the question and concern.
Dennis

[Fordeatinz71]

yea, i doubt it will get 15 with those gears and it being a 3/4 ton.  but everytime you complain about gas, throw a HUGE load in the back and/or tow a beast of a trailer and you'll remember why it's "ok" for it to get that bad of gas mileage!

[1976Scottsdale]

I would say about 12 as well since I run a TH400 4x4 3/4 ton, 3.73 full time 4x4 and a 305 and get about 14-16 depending on how I drive it.