You don't need mega horsepower for a Jeep to be competitive unless your on a paved dragstrip. My friend Burt bought his wife a CJ5 with the AMC 6 cyl. engine I think it was a 232. She got interested in pulling competition and did very well beating out a lot of sbc conversions. She wasn't satisfied so he built her a 400 Chevy engine. He had his own engine rebuilding bussiness. The 400 would spin the tires when the six would just dig in and pull. You can't win if you break traction and the 400 did just that. She gave up pulling and rock climbing and tried sand drags. By this time they had replaced the body with a complete fiberglass body and added a blower. On her third run she lost it and totalled the Jeep. She only recieved minor injuries thanks to the roll cage but there was nothing left that was useable on the Jeep except for two tires. I have a 4 cylinder cj3a that was better at pulling and rock climbing than the monster machine they built. I never entered it in the sand drags because I couldn't compete there but I only have $1200 in my Jeep and still enjoy it.