updating to a late 2.5 block

[Oringojin]

I'm in the middle of building up a new engine based on a new factory block I bought a month ago. I thought I got a great deal when I saw this block available from our biggest classic Porsche parts outfit here in France for only 2500€, and compared to getting my old block sleeved, which would have cost me around 2000€, I decided to go this way. I quickly figured out that there many changes made to the block over the years, and that I was going to have to replace a lot of the parts coming off my old engine, but the surprises have kept coming! I searched around this and other forums, and haven't really seen this subject dealt with, so I thought I'd put up a list of what I've found so far, which might help others in a similar situation, and get some feedback if I'm getting things wrong, or if I've missed things.

So far, here's what I've found:

Spring cam-belt tensioner (it looks like I could just install the stud from my eccentric adjuster and use that, but I've read that the stud gets tired after a few belt changes and should be renewed. OE is not available)

Oil pump (looks like there were at least 3 generations of oil pumps, pre 1985 which were very different and won't fit on a later block without modification, '85-'86 pumps which have the same passages as the later ones, but are taller with a boss for the eccentric stud and won't fit under the spring tensioner, '87 and later which are lower profile)

rear timing cover (I already cut up my rear cover to clear the newer water pump installation, but it looks like if I cut it enough to clear the spring tensioner it will be very floppy and weak)

balance shaft cover (again, 3 generations, and the latest uses different end seals and bearings from the 2nd gen)

oil return tube has an o-ring, no o-ring on pre 1987

Of course, the OPRV valve. I ordered the sleeve that presses into the block to use the earlier style, but I decided to pop for the 944Online OPRV in the post 1987 form in the end.

Anyone have any other observations? I'm all ears, since I just spent a weekend assembling this thing, and got ambushed by the oil pump! I'd be happy to get any other warnings or hear your experiences before I get back to it in a couple of weeks.