I'm dropping in a 78 "low compression" 460 into my 79 F-100 with stock gears, C-6 tranny, headers and dual flowmaster 40 series, kn air filter, and my tire sizes on the back are only 275 60 series 15's. I'm just hoping somebody can give me an idea of what kind of pick up will i be getting and any speed estimates you can give me (top speed, quarter mile). Also what kind of gas mileage and torque will I be getting would be nice too. Thanks

 

First, do you know what(if Any) modifications have been done to your 78 460?
Second, your quarter mile times will depend on how much your truck weighs, how much traction you get, and what rearend gears you have....
In a pickup, you wont be getting much traction to the rear wheels, because there isnt any weight on top of them. If you could find some way to get a couple hundred lbs over the rearend, you'd be great.
Secondly, you are gonna need to get wider tires in rear if you plan on running the quarter with a 460. I use 8" slicks on 14" rims when I run, and I get low 14-second quarters... But the car weighs nearly 5000 lbs.
Hopefully, you wont get that bad of mileage.. With stock gears, if you keep your foot out of it on the highway, maybe 12-14 miles/gallon because the truck is pretty light.
You should, if you get traction, run mid-high 14's with a stock engine.. Faster if there's any modifications.
One tip... .Invest in a transmission kit... _
Good luck!

J/.c

1965 Ford Galaxie 500 (okay, so not quite a truck)
460/C6 transplant @ 389hp/491 lb.ft.
14.29@103.8, 13-14 mpg heheheheheh