Well, an update to this initial post.
The box was installed yesterday, and when I went to reverse up the driveway, the car kept stalling.. I thought I had mis adjusted my clutch so did it again.. no, it was fine.
Gave it more revs to get up the drive way, and again it stalled halfway.. this time, the car was stuck in gear, with the clutch pressed in.. if I used my body weight to try and rock the car, I could force it out of reverse back into neutral and it would roll back into the garage.
Finally gave it a massive amount of revs, and shuddered my way up the drive.. clutch dust in the air.
Got it into first ok, and went to take off... really loud gear whine. If coasting, it was quiet but as soon as I cracked open the throttle, and put a very light load on, it would whine its head off.
Got into second, but it grinds and pops out.. have to nurse it home... cannot get back into 1st. need to come to complete stoop, then find first.. get it home.. really disappointed.
The box was just rebuilt by a retired porsche specialist. What could be wrong?
Before he rebuilt it, my only complaint was a VERY loud bearing noise which I presumed was a loose race in the diff housing. The box has an LSD and it feels like in reverse, it is binding up really badly.
I've started the removal process again.. so frustrating.. any ideas what it could be?
Should I pull it apart myself first.. I have done a few motors before and 1 901 box for a 914... But not sure different tools are required.
I am suspecting incorrect pinion depth as the source of the really loud whining.
In the videos below, I was holding my phone and trying to change gear.. the audio isnt the best.. a lot of the knocking sound, is actually from the front suspension.. but you can here the whine.
Apologies for the profanity.
I am gutted.
https://www.youtube.com/watch?v=M0sjodqPcWE