273 engine swap into a Jeep CJ5

Damn that sounds fun... I'm looking for more of a street-legal option that can give me more horsepower than this itty-bitty 4 cylinder... Does anybody know if I need to change out the transmission I put this to 73 in it? Maybe get a different bellhousing? There's a guy selling a 273 that is totally complete and only wants five hundred bucks for it... I don't need that much horsepower but more than a 4 banger... Thanks for the options!