mk1 caddy 1.8t conversion driver shaft

Hi my mk1 caddy engine died a week ago so i got a 1.8t out seat leon cuper R and i got a 02j gear box as well and the 100mm drive shaft flanges
so my Question is can i use my mk1 caddy drive shaft with 100mm cv joints or do i need different drive shaft  

I don't know which type of differential Cup, and or Axles that you do have.

I will tell you that if you had 90mm axles originally or what is equipped on it at this time, then the 100mm Axles will not work on 90mm Spindles (rotor/hub).

The 100mm Spindles off of a latter Cabriolet will go 100 or 90mm without an issue, the issue is that the 90mm spindle will not go to 100… There may be a way to do it but you will have to grind the 100mm axles down.

On the Standard Trannys on a Golf/Cabriolet there were two types of axles 100mm on latter Cabbies, and the 90mm that were more prevalent.

And swapping 90's in place of 100mm was simply finding 90mm cups on the differential, and swapping them over with the proper seals.

ok the cups are out of a 02A which are 100mm  flanges
to fit into the O2J gear box which are 108mm  flanges
my driver shaft are 90mm

i just got offered mk2 golf gti 16v  100mm drive shaft they fit in the mk1 caddy hub but guess they are too long

I believe your guess is correct..

ok thanks the only options i can fine is this set up

https://www.classic-vw.co.uk/mk1-golf-100mm-driveshaft-set-caddy-scirocco-20000-p.asp

is it mk1 gti shafts you are
after mate

mk1 cabriolet/ scirocco 100mm drive shafts 
That what I keep seeing to Fit the the 1.8t and o2J gearbox