I have read something online that seems to imply that X300 body structure is very similar to XJ40. I am contemplating swapping a 1994-ish GM LT1 V8 motor into an X300. LS1 is a better engine, but I don't think it will fit. An LT1 swap into XJ40 has been done before by Jaguar specialties. I am wondering if an X300 swap is possible.

 

Depends upon the year of the XJ40. The 93 (?) and 94 are different from the earlier cars. The later cars were redesigned to allow the V12 to fit, wheres the earlier cars were specifically designed so a 90 degree V8 i.e. Rover, would not fit.

 

Hi, any luck? I have a X300 with a AJ16 and also wondering if Ls engine will fit.....Thanks

 

Why would you want to get rid of the X300 6 engine. There has been some evidence expressed that it was designed to be the basis for the diesel engine which would made for a damn strong bottom end. When mine is at idle I cannot feel it running.

 

Just weighing up some options really, yes, it is a strong bottom end with large main bearings, the 4.0 has a forged steel crankshaft and forged H beam rods and a closed deck steel lined block from factory, so tough? Very, with quality bearings used too..It's also a good engine to use as a basis for a twin turbo or single twin scroll may also be a idea with fueling/intake mods.....