Alex,what is the std length of 3tj forks from spindle to top.

I don't know the length, without going to the garage with a tape measure...

I think that EC0 was refering to the option of using early R6 forks, which are considerably longer than standard 3TJ.
If I remember correctly, while doing the conversion on my bike, the two sets of forks were almost the same length, when stood next to each other. This coupled with the stepped 3TJ yoke, gave a slightly nose down aspect when using the new forks.

Alex.