i have a 78 f-150 with 351M C6 NP205, the motor has a edlebrock intake and i think 600cfm carb on it that runs excellent on the street, no smoke has plenty of power for a 78. problem is I'm going to lift it i think 6 inches and put 35's under it and right now it has whatever stock gears and I'm running brand new 32x11.50- 15 BFG all terrains and have been off roading a few times in a old sand pit a few trails with truck size mud holes and the truck has no power to spin the tires! in high range forget it because the truck just wines and then if it cant power itself out it just stalls. luckly low range has been fine so far in the sand pit but last night we took a ride down a trail that had really sticky mud and the truck almost couldnt spin the tires in low range and i almost couldnt get out. with 32 i would think the truck would be fine but its not and now im haveing to wait for the lift i want because now im gonna have to save money somehow and regear the truck for 35's. so my question is what gears should i go to?? i was thinking at least 4.56's, the truck will be driven in town only and towing my 14ft duck boat this winter and some off roading im planing on doing. what do yous think??

 

In town driving, you won't get your rpm's high enough to notice any ill-effects, and the 4.56 regear with 35's will bring your effective ratio back to just about a stock gearing set up anyway. I'm going to assume you have 3.55's right now, and if that's true, 35's and 4.56's will react just like if you had 4.10's in your truck with your 32's.

 

im not going to drive the truck on the highway and if i do ill stick to the right lane and cruise at 60-65mph. i just dont want to spend money on gears put the 35's on and then go out for the first time find out high range wont spin the tires and then put her in low range after im almost stuck and find out that low is just barely enough to spin the tires to get out, especially if i put a lunchbox locker in the rear which i might do also.

 

no body ever regear a dent before and give me some advice?