If you are considering the mugen clutch setup with a clocked .25, uh good luck. Melt down! My answer shoes held up ok with my clocked B5 but locked up too soon and stiffer springs would've caused a melt down. A phone call to Neal and you'll know what you need for the whole package. The .25 is a billy badass for sure but i'm not sure if i can drive it well. The clocked B5 is the perfect truggy engine in my opinion.