I had my 62 E for about 30 years. Went over the engine once. I was saving it for my retirement project to do a total off the frame, what there is of it. The doctor told me to get rid of cars and go to a truck, a SUV or have spinal fusion. That's when I realized I was too old to get in and out of the Jag. Plus in it's day regular gas was 97 octane. Jag liked the good stuff. I was looking for another head with lower compression. Couldn't find one. Had to retard the spark to quiet the chip munks in the engine.
That's when I ran across a guy from Chicago that restores Jags for a living. I sold it to him for 4x what I paid for it. No regrets. I hope he got it restored and it makes someone as happy as I was.
It's a wonder I didn't get killed in it. After the rebuild, I went for a test drive. Went to pass a person. Punched the gas and almost rear ended him. That's when I decided to turn before hitting the pedal. There weren't too many cars that could keep up with it. Perhaps the GTX might on top end. George