Nice truck worth spending money on. Staight and no rust restored about 30K miles ago. Needs very little.

Truck weighs 6200 lbs with 12 bolt 8.875 3.73 rear end thru mildly built 400 SBC with stock 400 TH. Tires are 31x10.5 R15.

If I'm going to keep the truck I'd like better fuel economy.

Talked to Dana at Probuilt about dropping a LT1 with 700r and trying to decide how much torque I had and needed to lower rear end ratio to 3.08 or somewhere between 3.08 and 3.73. Will have to change front unless I remove the 4 wheel drivetrain and front axle which I might do. Talked about torque fiqures with the current 400 as well.

He thinks that the LT1 won't work. 400 either without some more goodies. Told him I had an already built 454 30 over with cast crank, marine HD rods, good bolts, cast flat top pistons with 396 702 heads with big valves and about 100 cc closed chambers and oval port heads. Now that engine has 750 single pump Edelbrock and an Air Gap Permastar. Hyd Cam is 1303 Summit and will get 1.7 rollers or maybe 1.8 instead of current stock.

If I go to a 6sp manual with that engine thru 3.08 gears will I have enough torque to make that truck driver friendly and able to pull a small trailer and get some friendly fuel comsumption with maybe a demon or even fuel injection. Discussed 80E even with a GearVendor as well in all those combos.

I don't have exact torque figures but most of you can guesstimate what each of those engines can do.

I know it's kind of difficult to think of going to a 454 and getting better fuel mileage but he thought it might be possible with all the right gears.

And yeah I could buy a new truck and probably have a new truck with better mileage for a few thousand more.

Not sure this is the appropriate forum but I did think I would at least get some answers about going to fuel injection on that BBC.

So engines are LT1, 400 SBC and 454 mile street

Transmissions are 400 TH, 700R, 4L80E, 6sp manual with .75 to .5 6th OD.

Possible GearVendor OD

Change of rear end gears from 3.08 to 3.73.