hi everybody ! first sorry for the English im not very good ! lol but the question is ; I want to overall my 454 in a 496 and i want to know where i must stop to dont destroy my trany and my outdrive ! a TRS 1979 with a MERCTRANS by mercury so can i upgrade my engine with 500 hp and maybe 500 lbs of torque. thank you very much for your help cause now the engine is in the shop and im not sure to what to do with my broken 454 ! thank you again and enjoy your day !

It will be fine with 500hp and 500ft lbs of torque.

It is hard to break a TRS behind a Merctrans

Trans is the weak link there

thank ! anybody are able to find the spec of mercruiser ? another question for the engine ! i know im not in the good place for the engine but im better to oversize in a 496 or a 505 right now ? my fear is about the thickness of the bloc if i oversize to 505. do you thing my bloc could overheat if i oversize to much ? thank again guy ! very apreciate !!!!

Over heating isn't much of a issue in a boat when going large bore, it's cylinder wall cracking, egg shaping, and no room for future rebuilds. On a 454 stroker I'd keep the bore to a minimum. Like .030 to .060 over. 489/496ci

ohh ! alright ! im gonna keep my idea of 496 ! do you have recommandation for a cam roller kit cause i dont find a lot of those kit on internet and i want to do my homework before the guy at the shop told me some option for my engine !

what kind of tranny i could place there to replace this one ?

Do your self a favor and call Bob Madara for your cam and heads (585)654-8583.

+1, At the very least give him a call, he is a wealth of good information.