Installing a 4 speed with O/D

Greetings All in these strange times. I’m preparing my Mk2 for an MOD transplant - the old DG is showing its age. Already have an all synchro Jag box and my expert is sourcing flywheel and bellhousing. I’m leaving the automatic transmission tunnel in place but need to know where I should make the gear lever penetration. Any help or photos will be appreciated!
The underside of the console gives me the correct position for a Moss box per the second photo - but my new one will be different I expect ? Stay well. Thanks and regards, Paul

This is the position that I had on my original ‘66 ‘S’ conversion that I did back in the 80’s

This is the felt pad in my ‘65 ‘S’ that I am transferring the g’b into.
Interestingly that cut out is original? Hard to see but the distance is 110mm from the cross brace under the seats.

This photo of a 3.8 engine with a full synchro gearbox and overdrive may give you an idea of how far back from the forward face of the bell housing the gear lever is. Unit is from an S Type.

I have done something similar to my 420 G recently. What I did was to take off the gear lever, install the engine and gearbox and drill a hole from underneath the car where the lever should be to get an idea where I should start to cut the tunnel.

Thank you all gents. Using these thoughts I will cut the hole out today. Paul

A recommendation if I may, Line the underside of the shifter console with a “Dynamat” type of heat and sound insulation material. It makes a HUGE difference!


I lined the underside of the shifter console of the Mark 2 some years ago when I had the interior of the car reupholstered, one of the easiest things to do to avoid the necessity of wearing gloves…

I can do that - thanks. Paul.

Good luck… Please send us photos

I have let my MOD conversion to a marque specialist as I have started back at work full time. He sent me some pictures as below:
IMG_2001 IMG_1999 IMG_2012 IMG_2011 IMG_2013
Apparently the clutch masters are scarce at the moment - mine was $350. Ouch. Also my existing gear reduction starter cannot be adapted so I’m light another $400 for that.
The larger transmission tunnel in the auto means that clutch and gearbox work can be done without removing the engine (perhaps of use for next owner). Fitting a short overdrive with a “shovel” style gearbox mounting. Specialist repurposed my intermediate speed hold as new choke switch (formerly under dash). This now reads “choke”, no hole to cover or patch. Next job is to have a single piece tailshaft made up. Paul.

It’s probably a bit late now to mention that you could have used an S type clutch master cylinder and remote bottle. The later cylinder made by Girling (not Dunlop), was also fitted to the Rover 2000.

Your specialist should be aware of this Paul, but if not make sure that the mounting holes, for the S type / 420 rear gearbox mount, are tapped 3/8 “UNF, not left 5/16”. I prefer to add locking nuts internally to the two front setscrews also.
Peter B
Are you retaining the two piece prop or perhaps have considered the S / 420

Thanks for thoughts gentleman. Regarding the tailshaft, the new one will be a single piece unit as the MOD Mk2’s were originally supplied (as I am told). I will pass these thoughts on to my specialist. Paul.

Indeed, and hugely popular in many Formula cars.

The MK2 prop is not long enough Paul, the S / 420 manual prop is way to go.
Peter B
This assuming you have a short overdrive rear case and not the long MK2 version. Your description “shovel” indicates you have the short case.

I met a Mark 2 owner some years ago who had this conversion method done to his car. He also retained the speed hold switch and repurposed it as the overdrive switch. Fortunately, you have already obtained a steering column cover with a proper overdrive switch, so, of course, it makes perfect sense to repurpose the choke switch on the speed hold location. My choke switch remains under the dash, whe it has resided the last 31 years, Thanks for sharing the photos. Good luck!

Did you move from 104 tooth flywheel to something bigger ?
Or are there some finer differences involved in it ?

Should have explained myself better, intending to have one made up by Hardy Spicer. The Mk2 shaft isn’t long enough, as you say. Paul.

We did consider doing this as well, but the correct switch is being remade by SNG Barratts, in case anyone is interested. The overdrive indicator also from SNG. Per Peter’s reference the long series overdrives are now extremely rare, my shovel came from a 420 and was $100 from my favourite wrecker.
Not sure on the flywheel tooth count - my starter may have worked with a new pinion and a 20mm spacer. This solution pushes the starter forward and might complicate clearances. Given cost of a pinion and spacer along with the compromises we decided to go new. Paul.

Paul, I’ve never counted the teeth on a DG converter but I’d guess at 133 / 4…
The present high torque starter might fit if a 420 / 4.2 EType or 4.2 XJ flywheel and bell are fitted. The availability of this combination in the USA is probably greater that the 104 tooth flywheel and it’s all syncro matching bell housing.
Perhaps a check if the present high torque starter is the same as supplied for the 4.2 range.
Peter B