I have a 3EN2 trackbike & a 3TJ SP frontend just asking to be messed with. Has anyone put one of these in one of those before, any comments on this let me know, always get some useful info from you guys.
I know you have to use the 3EN2 stem as 3TJ is too short for the locking rings.

I think the 3TJ forks are a bit shorter than the 3en2 ... the TJ's headstock is lower

Measure the lengths of the forks, remember the TJ has a cranked top clamp