I race with my passion motor. My competition is a 535 trinity motor. We run pretty much the same but he has a little better chassis set-up. It think those jugs run around $3000 if I'm not mistaken. I only spent a third of that and I'm rubbin tires with him. If your not sure what you want, give Jim a shout and he'll work through it with you. I called Jim and told him I flattrack, he said ok, this is what you want.............................I said, do it. NO REGRETS!