About my Jaguar 420


LOVE it!!! Great story. Cool that you DRIVE yours. Seems like just about all other 420-Compacts are either junk, for sale, or both.
Would love to meet a 420 owner in my area, but I’d be shocked if there was even one other 420 in my entire State of Maine.

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Thanks Vincent!

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I had a maroon 420. It was a great car after I rebuilt everything. I drove mine alot if not daily at least weekly. Reluctantly sold it to a guy that really wanted it. I kick myself now…

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TIM!!! Tim Guntly??? I think this was YOUR CAR haha! I bought it from Thomas Potkefke who did MAJOR stuff to it making it even better. I’m very thankful for the great job you did rebuilding the engine (and trans? etc?). It runs killer. Thomas did pretty much everything that could be done to make it as reliable as possible, like German Hardi fuel pumps, a new HEI distributor, upgraded cooling system, and on and on and…
I do have some questions for you. I hope that’s ok.
It now has a more permanent home here in Maine. Love it! Glad I found you…or YOU found me!

It is. Some of the stuff he did I’m not a fan of, but if you like it that’s great! If I knew he was going to sell it so soon, I would have kept it.

But I have my dream car a 3.8 Mk2, but it’s a project. I’m preparing to sell my dads E-type and may buy a driving mk2 to have a toy to drive while building my other car. The project mk will have modified series 3 xj6 seats with xj40 foams and covers, 5 speed trampoline and triple SU carbs.

If you have any questions on the 420 let me know.

Of all the Jaguars that I’ve been around or owned, the one I miss the most is my '67 MOD 420. In my estimation, it was the best small sedan Jaguar ever made.


Thant’s good to hear Mr. Wiggles! I didn’t buy it because I’d rather have a MkII, or even an E-Type, believe it or not. I bought it because I dig sedans, and to me this is the most refined the sexxxiest, and by far the most unique Jaguar sedan of the era.

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Ok thank you.
I guess my 1st question would be; in your opinion what are the mods Thomas did do you not like and why?
Also have a few other questions if that’s ok. Would you like them here on or a direct message?

Direct message. I’ll reply there.

Wiggles, i"m sticking with my 3.8S, family owned for 57 years but if I had my choice I would have preferred the similar 420, not for the extra 400cc but for the better cooling system, potential AC, more spacious engine bay, bigger brakes and Variomatic steering…


Hey Wiggles, is there a thread showing your Jag powered Jeepster? I’m intrigued!

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The better cooling system was a big plus for me too.
Seems all the British cars I have / had, have a cooling capacity that works but only if all components are 100%. They are always on the edge, near cooking. It is a delight to have the 420 with its generous cooling capacity.

Much easier to just put the XJ40 seats in directly! I put Daimler XJ40 seats into my S-type.

I don’t want the power features or to hack up the crossmember. I’m welding the original base with tracks to the xj6 frames. The seat backs are a bit different, so cut and welding the top section with the bolster rods onto xj6 seats. The bottom will accept the xj40 bases directly. Yes its a bit of work, but it’s how I want it.

I’ve seen these done where the car gets hacked up or the seats sit at a different height and I prefer the seats to look custom made for the car rather than an afterthought.


But the exception to this inadequate cooling system syndrome are the Morris Minors which have an overly generous radiator.

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Helps, when the displacement of the radiator exceeds that of the engine…:wink:

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That linc was for a thread for E-Type headlight relays. Still can’t find anything on it. Am I missing something?

My Mark 2 3.4 which rolled off the factory assembly line March 31st 1967 was fitted with all synchro transmission, type ‘A’ overdrive, and Marles Varamatic power steering. When I purchased the car from the PO in 1989, I did not realize until after reading Nigel Thorley’s “Original Mark 2” book what a rare and desirable option this is. As for cooling, in 1998 I had the radiator recored with what is called a ‘recirculating core’ unit. Since that time, even on warm weather days here in Southern California with sometimes heavy traffic conditions, the gauge rarely goes above 70. All that being said, if the 420 had been available here in the US with the all synchro manual transmissions and Laycock de Normanville type ‘A’ compact overdive,I would have been very interested in such a 420 as an alternative to the Mark 2.