Lebro

Your steel washer is in the recess, which is only as deep as the washer thickness, probably to allow the larger springs to sit flat. I would guess that you have a 4A head, with 4A collars, but TR4 (or earlier) springs. Bob

TR2 / 3 / 4 valve springs are a larger diameter than later TR4A springs. your collars are probaly TR4A, & the springs earlier. Do the springs fit nicely into the recess in the head ? - they should. Bob

Nice work ! Bob

ARP lube easily available on ebay Bob.

Those oil control rings are a bugger to get right, they so easily want to slip one end over the other. Do make sure that does not happen ! Bob.

This is the type of thing I use, it screws into a threaded boss welded to the steel pipe in the bottom hose run. All the usual suspects sell them (the switch & the pipe) Bob. https://www.ebay.co.uk/itm/253043650850?hash=item3aea93b122:g:fwEAAOSwnkpa5z7W

Iain. No not the standard rheostat, but a 100 ohm wire wound "potentiometer" I used one like this: https://www.ebay.co.uk/itm/391584895037?hash=item5b2c47503d:g:IQQAAOSwLF1X9WZQ Then modified the spindle to match the "PANEL" knob I had Bob

Good point, I did have grind a bit off 2 of mine Bob

Just a dot of silicon in the gap of the viton seal, then as you squeeze it between the metal parts of the seal the gap reduces to zero. see this for the best instructions@ Mad Marx splitseal.pdf Bob

+1 Bob

I think it could be any of the helical cut gears loosing a tooth. Recommend a three bearing countergear when you re-build, & don't use cheap bearings anywhere on it ! Bob.

I was going to do that, buy found that the later springs were a smaller diameter, which meant also replacing the caps on all of them, & that the springs did not locate nicely in the cylinder head. Tests showed that the standard 4A springs were no softer, (or stronger) than my original TR3 ones. Bob

Have a great day Keith. Bob.

I didn't Bob

What Mick said. I had no means of measuring bolt stretch, so I used the torque setting given in the booklet that came with them. Don't have that to hand, & I won't guess. As I recall they can be fitted either way round, but could be wrong. Bob.