502 Mag to HP500???
 

Well I never saw myself going down this road, however my carbed 502 mag needs a rebuild. Its smoking worse than a weedwacker, wont idle, and is pretty much gutless. I have done some reading and from what I can tell the stock 502 mag and the HP 500 are similar as far as internals, block, crank, rods, pistons, heads(with the exception of valves, rockers, springs, lifters) etc.

I guess I am stuck at what to do. If the motor needs to be rebuilt anyways is it worth it to turn it into a HP500? I do not want to build a high hp un-reliable engine. I just figured that Mercury already did the R&D on the HP 500 so cloning it would give me more HP but not lose reliability.

Has anyone done this build and have part #’s for the parts needed for the conversion?