As most folks would say depends on time and money.

Do you want it to look stock? Replace the rear end and put in a 235. Do a search and you'll find lots of info on both swaps. This can be done with minimal investements.

Want a big engine and have lots of money? Replace the entire frame and running gear. You can buy a rolling frame from a number of sources, check out Progressive.

Good luck. Do lots of research here before you go too deep.