My approach recently was to find a procedure without messing around with timing marks, opening or closing figures of doubtful files of doubtful cams. So I got extra weak temporary valve springs that I use on all kinds of engines as well to find centre overlap at same lift both valves. For that purpose old valve covers were fitted with 8mm shank clock adapters. I had Sony encoders and a spare DRO for comfortable readings of equal lifts - on one pot, the rear only, first. So no gears on crank or idler fitted first. By hand turning the cam with soft springs I got the equal lift position and marked one suitable tooth on its gear plus a chisel mark on the engine case. So easy to get valve overlap anytime at this spot !
Next was front pot, encoders put on there and cam turned for same equal lift, tooth marked and chisel mark on case - overlap front cam this spot anytime, no guesswork any more with this set of cams and gears.
Next get timing disc on the crank end, find TDC by using a gutted spark plug for hard stop on piston by turning crank one way to stop piston on plug end, disc on zero - turn crank opposite way to stop, read degrees here. TDC is half way between both positions, so set disc to zero at this middle position.
Now for putting on all gears set crank at 4 degrees before TDC for rear pot. In goes the idler and rear cam set to chisel mark and its marked tooth.
Now get the half time gear of the crank and try to find one of the five slots that lines up with the slot in the crank end without turning the crank from its 4 degree position. Once that is done, gear on the crank, you can turn the crank one revolution plus 50 degrees minus 4 degrees for the front cam and its overlap. In this position you should be set to shove the front cam on its shaft unless its gear was not pressed up in a good position on the cam. The marked tooth is meant to line up with your chisel mark for the front overlap on the case.
I was lucky to have new original Andrews Mk 2 cams and gears I got 30 years ago, all perfect.
After all gears are marked with their chisel marks and half time gear installed you can take off heads and mount the original valve springs for good and finish the engine.
The 10mm alu pushrods can be a positive mod, heat extension fits better with all alu engine and look stiffer than the knitting needle originals. But the lineup with the follower cups was not correct as standard so I had 1 mm offset sealing cups with slim o-ring glued in the case for more clearance of pushrods in there. Pushrod shrouds shortened to max bottom length less than big recess in case for this mod to be able to assemble with offset.
Vic