ok,i own a 72 swb f-100 302/c4,and a 3.25 rear end.my question is ,how can i make it so my truck can go fast on the freeway and get good gas milige...when i start goin to collage i will be driving about 40 minutes everyday,so i need good gas milage,and i dont like 65 as a top speed,wut should i change my rear end to,is there a company that makes a o.d. unit for the c4....ummm,any engine mods ...tire or rim size,i must know,lol,thatnx for ur help.....

 

my 87 f-150 has a 351w 4bbl, a c-6 with 3.55's and 31's and i get 13 on the highway. take it for what its worth, you have higher gears, but not sure what else you could do to make it anymore efficent, i currently travel 35 min to collage every day (well mon-fri) and when i was running my truck before i started a rebuild it was expensive. my best advice, is to get a beater to travel with.

 

My old '70 F100 has a 4bbl 390, dual exhaust, with a C6, 3.50 gears, and 31's out back. It's got a Holley 600 cfm vacuum secondary carb and Duraspark electronic ignition with a Comp Cams 268H camshaft. It'll do a buck ten on the top end, but for the best mileage it likes about 50 mph. Mileage is usually around 14 mpg.

If your truck can only push the speedometer to 65 miles per hour, I think you've got a seriously weak engine, the wrong gears, or a combination of both.

Let me start by saying that the tune up is critical to mileage. Getting your engine running in tip-top shape should be your first priority. It would help to know what kind of compression your engine is capable of. I'd start with a compression check. Your best cylinder should be within ten percent of your worst cylinder. If the compression check fails, then an engine rebuild is probably in order. It may hold together for a long time, but it will never reach it's full potential.

Your points should be set at .017" gap, or 29-31 degrees dwell. Make sure your mechanical advance is working properly and not frozen up, and be sure your vacuum advance works as well. Initial timing should be set at 6 degrees before top dead center. Your carburetor is in good shape and the filter is good, right?

Check that your tires are all properly aired up and that none of the brakes are dragging. Also, any unnecessary weight will hurt mileage.

On a side note, I spent 40 minutes looking for this thread:
https://www.ford-trucks.com/forums/s...ght=6772+tune+

only to find three red x's in boxs... :-(

 

well,it goes alot faster.but i mean its rpm's are way up there,and all tires are aired up,i just replaced my distributer,i rebuilt the engine,the compression is perfect,all sparkplugs and points are perfect.everythings in place...oh one thing i wanted to know is if anyone makes a turbo for or 302's.....but i mean i just want the best gamilage possibal

 

You might try to find some 2.75 gears to drop your cruising rpm, but you'll also hurt your take-off at the same time. I have a '78 F150 with a 460 and 2.75's. It spends a lot of time in second gear while towing, but runs great going down the interstate.

 

Good luck with college...