2nd gear problem

Ok so i had my tranny rebuilt because 2nd gear was grinding and eventually wouldnt even let me into it...

got the car back and everything seemed fine. turned out one of the keys in 2nd broke and messed up some other ****..

replaced the synchros, keys, shift forks, slider etc etc pretty much everything except the speed gear itself...

now my mechanic is a gm master tech who specializes in T56s

when i try to shift from 1st to second fast it grinds... whether or not im on the gas hard just as long as im trying to shift hard

Like i said everything is brand new except for the speed gear, the tranny has been taken apart and looked at 3 or 4 times and everything looks fine...
he thought it may have been clutch spin down so i got a new spec 2 disk and reused the old spec 2 PP (only had ~10k miles on it) and an slp billet flywheel and all new clutch hydraulics.. no luck still does it

he said all he can think of is somehow the shifter (pro 5.0 but i dont see how it could be that) or the speed gear itself (but he looked it over and it seemed fine)

what could this be?

What kind of fluid do you have in it ?

uhm i used to have royal purple in it but for a while it has had whatever they have at the GM dealership where he rebuilt it

You definately have an issue . I'm not saying your builder did something wrong but it sure sounds like something is not right in it .

I understand the suspicions of the builder seeing as it is all brand new parts but like i said, he's rebuilt all of my friend's T56s and nobody else has had a problem... its not that he's just my builder he is a friend and comes out racing with us frequently... he's be the last person i would put it on...
all parts used were upgrades.. billet keys... carbon sychros... billet shift forks etc etc

when we just replaced the keys in it and whatever was broken he took it out and apart a second time for no charge other than the cost of the parts when it still grinded, he's a very stand up and knowledgeable guy... he tore it apart in front of me and explained everything i asked him..

im bringing it back to him in the next week or two after he gets finished with some jobs because im doing a cam swap and i want 2nd gear fixed at the same time..

so i was just seeing if anyone had any other suggestions on what it could be... maybe the shift mechanism got some of the broken piece stuck to it? but id imagine it would do it in more than just 2nd gear... i can bang every gear except 2nd grrr

any other thoughts?