I did quite a lot of work in and around Jags at the time these were shipping. The 6 cyl engine came in 3.6l AJ6 and 4L AJ16 versions as far as I am aware. I never came across a factory or dealer turbo. It was not an easy engine to mess with due to heat issues. TWR and Lister did some conversions but these were mainly bodywork and brakes. Most upgrades focused on the 5.3 V12 and took it out to 6L which was a common conversion at the time for the saloon and XJ Coupe.
They did a 2.8 six for either the MkI or the MkII XJ6 and it was the only model offered with an optional set of foot pedals and chain drive.
