Im not big fan of Jacks work, ( Jack I will leave it alone here) I ended up taking my daughters LT80 to Tudors, thing ripped with stock pipe , stock carb,changed the gearing to early years and 428 pitch,  did wheelies with Jeff Tudors riding it, You know me I love to hot rod these quads, I save the cash run the stock pipe or keep hunting for LRD pipe, use that money to upgrade the shocks, be surprised how much mor eyour kid will peg the throttle with the shocks set up for taht LT80.