A few Photos of my 4 year project:
12,500 USD invested in parts so far...
4.2 rebuilt engine from 1987 XJ6, BW35 trans, all LED lighting, Touch screen stereo with subwoofer, backup camera on license plate frame...
work in progress for a old guy with a bad hip...you should see how slow i work with a walker !

 

The Jaguar 420 with the 4.2 litre engine was never fitted with the BW35 gear box which was used in its sister Jaguar the 3.4 and 3.8 S Type due to the BW35 not being able to take the torque of the 4.2 engine according to Jaguar. The 420 was fitted with the Model 8 gearbox from earlier cars as it had a cast iron body where as the BW35 had an aluminium casting. The XJ6 4.2 was fitted with the BW65 and BW66 gear boxes. I believe
No doubt the BW35 will hold its own but try not to bury the right foot too often or the gear box might tear itself to pieces.

 

it must be an bw65/66 because it was attached to a 4.2 fuel injected engine from a late 80's XJ6
i paid 500 bucks for the pair with torque converter, and the downshift is a cable

also i found an intake manifold with 2 Stromberg CD 175 carbs because im not able to do fuel injection, due to missing parts

i hear that the electronic distributor is set up with a vacuum diaphram for fuel injected engines and i have to change the advance cannister for more low end torque.
also the fact that this is a fuel injected head with larger intake valves might perform better than the older heads.???