What would be better I ride a lot of roads and do hill climbs I'm thinking of an athena 440 kit or a turbo idk what else I would need besides the kit to do either of them or witch one would give me the edge against my buddys yfz450

 

The 440 kit gives you a good power boost, but remember, that is pushing the limit on the jug and it is only an air cooled motor,trying to push enough hp out of it to match or beat a race-designed liquid cooled 450 is going to be hard. I have heard of a lot of head gasket failures and studs pulling out, don't know if that is because of the kit, or incorrect installation, my son has a used 440 that is trail ridden aggressively, havent had a problem in several years, but if you are hill climbing and racing, I can't say what the life expectancy is on a 440 kit. Not sure of the cost of a 440 kit, but you may be better off in the long run saving up some money and selling the ex for a good used 450 style racer.

 

I have heard the same thing about the 440 kit. The engine won't last long.