Trex (73.50 bore x 61 stroke = 518cc) Drag ported by Rudy Kurtz (Port Magic). Hone marks still viewable on cylinder walls. Comes with good reeds and cages, Intake boots need to be replaced, Trex 7 mil block on a 73.50 bore, 73.50 pistons and rings, Power valve block offs, Trex head with domes and exhaust flanges. You will need a 7mil crank(115mm) to make work right Asking for $1000.00 obo send me your email address and I will send you some great pics I tried to post them but you can't see nothing after I crop it to make it fit.