I did the fj40 cummins 6bt first gen conversions.... All About Transmissions in Ventura California did the conversion start to finish!!!! It is one hell of a beast!! A large job, lots of parts in the gear train were changed to make the job complete and strong for the cummins 6bt!!! I have had it on the road for two weeks now, it is my daily driver. I am getting @ 24 mpg out of it, tons of power and loads of torque!! I have had several cruisers with every different engine combo out there and this takes the cake... This conversion is not for the weak at heart conversion guy, budget was a lot, but worth a lot more!! Priceless!! Want to build another just like it for my 14 year old son so it is ready for him to drive. My truck is a 75 fj40 and I wanted the 6bt cummins , NV4500, bolt yoke shaft tcase, currie hi9" ford rear end, for pinion height. All About Transmissions Did fuel pin and 366 gov spring inside fuel pump!! This truck is amazing and fun!!!