green92camaroRS

Hello all, I'm a new member here but have been using this site for about a year now. I have a 92 camaro rs 305 tbi the L03 motor. So here's the deal I love my car and don't want to sell it but the engine has been acting up lately and now the exhaust has all but fallen off and I mean like I have 1 tail pipe now... BUT I won't sell it too much in it now. So here's my dilema I want more power obviously but I'm not sure if repairing and building the 305 is even worth it so I was thinking 350 tpi would be a good swap and even found a brand new motor I can afford but I know my cars transmission won't hold. It already grinds and it won't stick in 5th gear so what should I do? If I need a tranny point me in the right direction. Sorry its a little wordy but I figured I'd save some back n forth talk, I'm no mechanic but I know I can do this swap so please any tips would help thanks all