Having dumped a ton of money into my 258 I can relate to what you are looking at. With the feul injection, all ignition pieces, header and exhaust, I have spent a bunch. Now It runs as better that it was ever meant to drive from the factory, but for all of that money I could have dropped in a 300HP small block Chevy. If I had it to do all over, I wouldn't spend a dime on the 258. Don't get me wrong, I love the way my jeep runs now, but just imagine what that small block would do. Just my $.02.