Thank you! Sometimes to best way is to just get on with it, however I’m beginning to think I should have just put in another triumph box haha

Well, today I went for the first drive with the 5 speed. I got the clutch release working by some miracle, and then spent around 6 hours modifying the exhaust headers to fit around the starter.  Got it all together and took it for a drive, it works. It shifts into all 5 gears lovely and reverse too. However when I had it running on the jacks and went through the gears it was vibrating itself to death any rpm over idle, the higher the gear the worse the vibration. This vibration was not noticeable on a road test which is strange but things act differently under load, and I only took it to around 40. Also I can hear the clutch release bearing dying. The bearing was *just* big enough to use the triumph pressure plate, or so I thought. Presumably I need a bearing with a bigger contactpoint/diameter, or a pressure plate with a smaller internal diameter.  The clutch also has small amount of travel and feels weird, not sure when it’s fully depressed or not. I’ll have to make some revisions there. And the exhaust headers are blowing from somewhere, obviously when welding I’ve missed something. So few things to be getting on with there, I reckon I’ll get a custom prop shaft made as that vibration was terrible and I don’t want to risk it killing me, Nick Jones you can say you told me so.  Also I think I’ll remake the spigot bearing, I bored the centre out a little more than a meant to to fit the mx5 box, but I thought it would be okay. I’ve got a spare so I’ll take 14.5mm out instead of 15. The starter sat too far into the bell housing for the revised flywheel position so i just spaced it out with a couple of washers which did the trick, I was going to make a proper plate but there is no flex here so I’ve decided it’s fine also that starter motor is far too close to the exhaust, I’ve probably got around 5mm clearance, I’m going to make heat shields to prevent some of the heat but in my experience on cars it’s the electrical components exposed to constant heat cycles that fail first so I’ve got that look forward to. like I mentioned before I am putting a different engine in eventually and it will have a totally custom manifold so it won’t be near the starter. I only need this to work for a couple thousand miles.

I think you would want it to ensure the excess fuel is returned to the tank in use. Unless you ensure never to fill the tank in question to the brim. And avoid idling/small throttle opening with attendant high fuel bypass for extended periods Or always drive flat out so there is no fuel return

Oof, Le Mans wheels! But £1400 for 4. And what size is 14.5x6.5...?  https://www.ebay.co.uk/sch/i.html?sid=godinsltd&_pgn=1&isRefine=true&_trksid=p4429486.m3561.l49496

Naughty boy 

Wrong engine size and external slave not internal concentric……

Out of my budget at the moment, and very likely wouldn't fit my mk4, but there's a rather lovely looking GT style hard top and bonnet on ebay at the moment: https://www.ebay.co.uk/itm/376063269177?_trksid=p4375194.c101949.m162918

Some lovely modifications, and then someone has put those awful tiny foam pancake filters on the air intake!

John Below is an edited version of the later XJ fuel system, from SC Parts. The device you have is a changeover solenoid, which would give you remote control over the tank you are drawing from (item 37 in the diagram). The fuel return solenoid (circled on the return feed diagram) would control which tank excess feed is returned to by blocking/unblocking each route. I suppose the question is whether you would need this, or, given your likely rate of consumption, simplify the installation and pipe to one tank for your return fuel? Paul