How do I get more top-end power?

chrisn8

I have a '78 F-150, 4x4, dual exhaust/glass-packs, 351 modified to a 400 - recently rebuilt. It is geared low for towing power, and does'nt seem to get the speed it should, is there anything I can do to give it more top-end power? Also, are there things I can do to increase my gas-mileage. Please e-mail any suggestions to midknite72@hotmail.com. I really appreciate any advice. Thank you -- Chris

akjbmw

Compare the cost of potential engine mods to the cost of a GearVendor or USGear (I think those are the names) overdrive units. You indicate you are "geared low for towing power" so an overdrive unit should bring your engine speed down or vehicle speed up (half full or half empty). This will lessen the "sprint" effect at highway speed too. I think it's a leverage thing.
Good luck.

cobra98

Have you considered/added headers and dual exhaust? You should have plenty of room for them. You might have to have the exhaust pipes custom made though if you have dual tanks. I had that problem on my '85 F150. Should certainly help.

saddaddy

lariat1

I agree with Saddaddy about all you can do is swap out your rings and pinions. If I remember right a 78' ford had two choices for rear end ratios the "high" gears were 4:10's and the "lows" were 4:56's. Your best bet would be to slide a set of 3:73's in the pumpkins.