I have the raceporting an head work done from HPD an retarded the timing. The motor is strong has good pull the motor only gains 250rpm's from the mods. So red line is 6750rpm's for the motor. Im running 100 oct gas that is what Daryle at HPD told me to run in it. Im thinking with the mods I have plus the weight an putting 20" tires on the rear I have 18" now I think I could hit 60mph. When I first had it an did some small changs I had it up to 50 to 55 on tar. This is going off the speedo from a 96 400 explorer. If someone has a 34mm carb an pipe an have about $260 plus the money to have it bored plus a new piston it is well worth it. All together it is $410 for the bore an piston an machining.

 

Thats $410 for boring, porting, wiseco and headwork?

 

The porting is $200 head work is $60 the Piston is $98 an the boreing was $50 from my Polaris dealer. An you need the 34mm carb.