Are these still available for the 4.0 anywhere? All the old links people posted on old threads are to dead sites.

 

What are you under-driving ?

What are you trying to achieve ?

Ltr

 

the crankshaft I suppose. I’ve heard it’s best bang for your buck to free up power and give you a little boost.

 

From what I have read it works too, are they available, you need to check it out at one of the Auto Performance Sites, i.e. JEGs, Summit, etc. !
Question is can you live with the result of less electrical power in your vehicle, headlights may decrease in brightness, audio amp won't bang in with full power, the engine itself may run worse without the full power of the alternator to run the electronics and will the engine keep as cool without the full flow of the Water Pump; there are always trade offs !

Good Luck on your choices, check out the High Performance Sites for engine accessories or Performance Adding Devices.

Sorry for getting carried away, I don't believe in the Pulleys Systems to gain power in a DD.