I have a 1985 f-150, and it has a 4.9 L under the hood. The only problem is i want it to be a 4x4, not 2x4. I want to lift it and put a pair of Dana 60's under it, I am wondering if anyone thinks that there will not be enough power to push it along. There is an old 460 i could use, but i realy like the realiability if the 6. Ohh yea there will be 37 in. tires under the truck, just some more info about the power going to be needed.

 

The Ford straight 6 is evolved from a tractor motor. There's plenty of torque but not a lot of horsepower. The motor will move your big truck just fine if you gear it low enough and never want to go over 50 mph.

 

I used to have an '87 4x4 reg cab Lariat with the big inline 6. Didn't do too bad, topped out at around 70-75 if I pushed it.

I had the manual locking hubs. With the hubs engaged, around 60 was comfortable but the mileage really sucked.

 

I had a 95' RC 300 w/5sp. It had a Flow, punched cat,K&N,hotter coil. After disabling the governer I was covering a mile in 33 secs averaging about 116. My friend had a 99' 2 door tahoe 350 with and a programmer and K&N it was auto and 4x4. I would take his truck from standing start to top speed easily...never seeing him again. My 99' RC 4.2 5sp with Flow,K&N and EGR disabled will blow the 95' away, but does not have near the torque. Do not bother keep the 300.