bolt on horsepower for pre ho 4.0

[1983Bronco]

My new ecors rig is running 1990 jeep cherokee with the 4.0 and the crappy pre ho fuel injection system, just doesnt have quite the kick the later models do. Anybody messed around much with these. Looking for a little more power for the race. Thanks

 

[Hurley]

I'm not a 4-0 guru, but I'm going to say anything short of a supercharger running at low boost is not going to be worth it on the scale of items that can be bolted - on a power/cost comparison (and a supercharger is expensive, obviously).

my recommended list would be:
- cone filter (with adequate guarding)
- better muffler (if stock)
- port & polish the head (if you are up to the challenge, not bolt on, but it can possibly be free + gaskets/labor)


can you ditch any more weight from the rig? what gears are you running, and what range/ratios are you choosing?