Got several things planned, but not sure what to do next. I want to change my muffler from Flowmaster to a Magnaflow, get the underdrive pullies when they come out, and also change my gears to 3.73's (got 3.08's now). I've got the option of either changing the gears, or doing the muffler and the pullies. Eventually I will do them all, but I'm not sure which will produce the most gains for the short term.
Does anyone have any thoughts on which to do first?

 

I have looked and looked for underdrive pulleys for a 4.2 I did an engine swap so I dont need them anymore but my neighbor would be greatful If I could find them for him. Do you know where I could get them or a brand name?? Thanks

 

ASP racing is testing them now. Talleywacker has the prototype pullies on his truck. I sopke with them this week, and they said they should have pricing and availability in the next few weeks.
www.aspracing.com

 

The gears would give you the best *bang for your buck*. You will feel the difference. You can get it done if you do it yourself for around $200. I would reccommend using only ford motorsport gears and renting or borrowing the proper tools like a dial and a good set of ft/lb and in/lb torque wrenches. It's not that hard if you have instructions with you and follow them well.