ok i had a crack in my cam chain tunnel on my 100cc jug so i just bought a 125 jug off of ebay. should i use a 84 125 piston or a 02-06 drz15 piston? i can get a new 1984 125 piston and rings for $55, vs a 02 drz125 piston kit for 90 on ebay. is there any performace increase? higher compression between the two?