i have a tricked up BW40 with a 2000 stall etc. and was just curious as to how much stronger a 51 is than a 40? i have heard they are stronger but also shift better so i was just curious to peoples thoughts. also is it a straight bolt in job to put a 51 in an XF. the only obvious thing i can think off is that the bell housings will need to be changed

cheers

The 51 will bolt staight up to your bell housing (use the 51 convertor). You can just change Valvebodies if you think they shift better. Also you will need to check the Kickdown cable as it probably will be longer (which is not a real problem, you might just have to make sure it doesn't get burn't or caught on anything) . You will have to check what your 51 is out of as a EA 51 has different rear cross member mounting hole centres. If it is out of a XG ute or van the mount will be the same as an earlier Ford. If it is out of an EA sedan you will have to change the rear transmission mount. The 51 in theory is a little bit tougher in side but they still have some weaknesseor problems.