I have a 400ex and love it but I was looking at getting raptor and then I thought about putting a big bore kit on maby 416 or 440 or bigger or anything in between there to beat or at leats keep up with raptors. How reliable do these kits make your 400ex? And do you like them and how do they compare plus do you have to burn racing gas in them?

 

The 416 kit revs faster. the 440 kit has lots of torgue. either way they are a big help from stock. add a cam and it is even better. You don't have to run race gas as long as you stay below 11:1 compression check out my web page has all the parts you are looking for colbykostman.tripod.com

 

If you really like your 400 keep it and get one of these kits and put it on, believe me you won't be sorry you did. The difference is night and day, it's hard to believe how much more power is hiding in this motor waiting for a wake up call. If you have a reputable shop do the work and you take care of the machine (change the oil often etc.) reliability won't be an issue.
www.Powroll.com is who did all my work.