I have a 87 F.150, i converted it from 2wd to 4wd, it has a C6 and 3.55 gears, its an extended cab long bed, it used to have the H.O. 351, my new motor is a 351 from a fuel injected 89 150, i know i can swith the intakes, put my edelbrock performer intake on it, and put the distributor gear on the fuel injected distributor on the old distributor

Now i want to do a little bit of towing with it, towing about 5,000 lbs, it has a 6" lift with 35s, i mite put 3.73 gears, dont want to got ot 4.10s without overdrive, what cam do i need to boost towing, i know nothing about them, also i want that cam rumbple at idle if at all possible
sorry for the long post, just had to include everything

 

are you running stock EFI? If so you won't want to get an aggressive cam since it'll confuse the computer. I'm running a crane 444232 cam, but they may hard to come by these days. Comp cams makes an equivalent 35-255-5, just be sure to get one with a lobe seperation of 114.

You may want to consider 4.10 gears if you're sticking with 35" tires. That will be the biggest bang for the $ that you could get for towing. I'm running 3.73 gears on my truck with 31" tires, but I'm looking to get smaller tires now for towing. The windsor pulls best at 3k-3.5k rpm, right now I'm hitting 3k at 63 mph, I want to lower it to 60.

 

Assuming you are using a carb on the '89 motor get the Comp 35-238-3.