I'd just keep the powercore. There's some better ones out there, but not signifigantly better. Spend the money on something else like a hi comp piston. And yes speedy, DG exhausts are generally junk. The new bullet series they came out may finally be up to par with other companies, but they are still overpriced. I wouldn't be spending money on porting, carbs, cams, etc on a quad you're planning on selling. I'd just get it rebuilt with a high comp piston and leave it the way it is until you sell it.

 

isnt porting only like $60 and dont it give you like a huge power gain???

also if i just rebuild it and put a high comp. piston is that gonna be a major difference in power

and should i get an oil cooler with just a high comp piston.