G'day mate,

Fred Stevens has a great write up on this in the Tech Tips section. I put the 3.55 kit in my 41 at the end of last year. I thought long and hard about whether to do that or go to an open driveline. Whether its worth it really depends on how you use the truck. The 41 is a daily driver for me and I do a few longer trips. There is a noticeable drop in revs. With 31 inch tall tyres the truck would cruise happily at 50mph. Now it cruises really well at 60 - 65 although I usually sit at just under 60. If you do decide to put in the 3.55 get the overhaul kit as well and replace all the bearings etc. If you have any more questions, fire away. Welcome to the bolt.

Bob