I forgot to add, definitely recommended for serious road racing car.    As, for guides, we use these https://www.cheprecision.com/part/guides/?srsltid=AfmBOoqrW1ONHCwfihciAhjKjMBQ8ftIHY_eyql4_aDjIq23ObAUFTJa understand that the guides need to be sized appropriately. 

Yikes, those are big.    The aftermarket spring oilers used here in the States in roundy-round cars typical use 2x .65mm holes per spring. More cleverly, they use Holley carburetor jets as their meter into the oil manifold. They usually recommend to start with a 0.028”-0.040” jet. 

Wouldn’t have thought it possible!

To me, the shape of the wear mark, a definite straight edge, (which I think marks the edge of the rollers, though not sure if front or rear edge), then the “semi-elipse” is indicative of either misalignment, or a slightly flattened section in the bush (perhaps due to a burr forming under it as pressed in. It obviously isn’t much if it’s not detectable as stiffness when assembled, but unfortunately doesn’t need to be much - full house needle rollers are not at all tolerant of misalignment.  Shaft hardness will be a factor, but only in the rate of wear. The needle rollers are really hard. The bush inserts could be nearly as hard too.  I fear that even if you are able to find a properly hardened shaft (assuming the current one is not), though it might last longer, it will still wear prematurely and in the same way. Not sure what to suggest. You could kick the can up the track a bit by flipping the shaft through 180 (reposition the roll pin) to put the load on the other side, but given the mere 6k it took to generate the current wear pattern….. it’s not an appealing route except to check that you get a repeat of the same pattern.  Shining a bright light up the bore might show up a witness mark on the bush bore.  In past days I’d have suggested buying up a couple of cheap non-OD gearboxes and praying one yields decent parts to use instead. These days though they aren’t cheap and are usually knackered!  Do you have any friendly precision engineering works locally you could approach for an opinion on the bush alignment and whether it’s measurable?

Back where it belongs! Quite the fight with the tunnel in, was just stopping the box from coming up enough! Thank God it's plastic and not the cardboard one, I think it would have punched through it There really isn't too much more to do until the head is machined, most I can do is fit the filter housing and new filter. The jobs are getting few and fewer! There will be a few puzzles left toward the end, things like finding the missing y piece for my 6 2 1 mild steel manifold, the air box arrangement( make one or modify a standard one to fit hs6), needles, springs, things like that. I honestly can't wait to drive it again

Thanks Nick, yes absolutely, I hope it pays Haha yes yes don't worry, The ports are seared into my brain the amount of time I spent working on that head back in the summer

What they said already really. I did loads of reading on this before building the Vitesse one. Ultimately, real world packaging constraints usually dictate.

Never knew such things existed. Good idea.   Would be easy to make fixed length ones and you’ll likely find in most case you do use a particular length most of the time.

Good work. The OCD is strong in this one  You know the front valve is an exhaust valve right ……. (I have that t-shirt )

I have a 123 in my spitfire, it's been 100% reliable, was fitted 7 or 8 years ago. I know a lot of people have issues with them, but for me it's been faultless. My car is layed up for long periods and I was constantly having issues with corrosion on the points, no such issue with the 123. My only annoyance is mine was pre app, so you basically have to take it out to adjust it.