I have an 86 Dodge Ramcharger 4x4. I installed a 84 remanufactured 360 in it, then put on a set of 33x12.5 tires. Now i have some problems. I'm getting about 120 mpg. I have no power and when i try to even clim up on the curn in 4 wheel it feels like the front tires want to but then fail and the back tires will just spin when i give it gas. And when its wet and i try it, with it in 4L, there's so much power the back tires want to spin even while i hold down the brakes. This is my first 4x4, and i love it. I just have a lot to learn. I figure this is the best place to start. Thanks for the help.

120mpg???? damn that's good.

is your front axle auto hubs or lock out?(do you have to turn the hubs)

if you have auto maybe they aren't engaging.

120 miles per tank......

Its auto lock hubs. I went back to my 30x9.5 tires and my gas went back to around 15mpg.So thats good. Im getting my gears changed out for 1200.00 big ones, and their going to put locking hubs on as well, so thats not too bad.  I do thank you for your input and im shure ill have a lot more questions to be posted soon. Once again  thanks

I have a 1986 dodge with 36'' MT tires with a 318 360 heads it pulling around 400hp with locking hubs I have never had that problem with my truck if i lock in in 4l hold on for your life? in the snow its great try some new tires//// that might help thanks Mopower_1  

I love some of these HP guesstimates. I would like to see some of them on a dyno.  

well he did say around 400 hp LOL you prolly have a bad switch in the top of your tcase or the cad (central axle disconnect )unit on the frt diff is not working due to a broken/worn fork or spring