Fuel Mileage Check '69 C/10

[VWNate1]

250 CID L6 , 350TH LT235/75.15 Radials , PS

16.2 MPG , not too bad , I'm hoping for better once I get the cylinder head rebuilt , better yet if I can figure out the 700r4 tranny swap .

[72peace]

I'm swapping my th350 for a 2004R it's a much easier swap and if rebuilt a much stronger trans. No cutting of the drive shaft, uses the predrilled holes in the 400 position for the crossmember. etc. And much better gas mileage on the highway.

Just a thought, cheers,

[mrein3]

Originally Posted by VWNate1

250 CID L6 , 350TH LT235/75.15 Radials , PS

16.2 MPG , not too bad , I'm hoping for better once I get the cylinder head rebuilt , better yet if I can figure out the 700r4 tranny swap .

Be careful with an OD transmission. If you're getting 16.2 now, that is stratospheric high for one of these trucks. To get that kind of mileage you need a small, gas sipping engine - which you have - and "highway gears" in the rear end. I'm guessing you have 3.08s in there.

Long story short - folks that have 3.08s and put in a 700r4 or 200-4r have seen their fuel mileage DECREASE because the OD gets the engine in too low of a rpm band.

Before you spend any money, check out what rpm you're running at the speed you're going to be using most of the time.

[VWNate1]

THANX for the heads up ! .

I guess i'll have to pop off the derby cover and have a look .

It has a 250 now , I bought a 292 but those are pretty thirsty so I may not use it in the end .

I *do* need to have the head re done , the valve guides are terribly wobbly so it smokes on trailing throttle .

The HEI seems to have cured it's constant oil fouling of the spark plugs though .

I only get about 200 miles per quart , was far less when i was running thin synthetics , now I'm using Dino 20W-50 and thinking of going to straight 30W if I can still find it anywheres .