I blew a head gasket earlier this week, and while I’m already on the inside of the engine doing all that jazz I was looking around for some tips or suggestions while I got everything torn apart to add a bit more torque, I am looking for nothing crazy, but I would like a little bit of a hauler out of this little 4.0 if possible

 

Welcome to the forum

1991 Ranger 4.0l 4x4?
Manual or automatic?

You have a 4.0l OHV engine, used in 1990-2000 Rangers, 160HP, 220ft/lb torque
2001-2011 used the 4.0l SOHC engine, 207HP, 238ft/lb torque

4.0l OHV does pretty well as is with 220ft/lb torque
There are upgrades to roller rockers and heavier valve springs, but pricey, and not a lot of "bang for the buck"
Look here: Tom Morana Racing Engines

Changing axle ratios gets more lower end and pulling power, but gets pricey for a 4x4

Ford, like other car makers, sell performance, so if there was a good "bolt on" product that increased performance then they would add it to an engine, that's why all Rangers 1985 and up have Factory Cold Air Intakes, a cheap "bolt on" part that helps performance


Automatics are stronger than manuals so will always have better pulling power for hauling stuff, i.e. trailers