vpi tnt still a performer?

Air bladder feet were introduced with the release of the TNT Mk4.  There are few early Mk5 with air bladder feet until existing stock was depleted.  The Mk5 used racquet balls for air suspension (no leaks)

It sounds like your table is a Mk3 with spring suspension.  The holes on the top of the corner support towers have a 1/4-20 threaded set screw in which the spring suspension is supported. You adjust the set screw to level the table.

If by "ribbed" platter you are referring to a platter with drive belt grooves cut into the platter's side to help prevent belt creep, then you have a TNT platter made from a combination of aluminum and delrin. A very nice platter.

The Graham 1.5 is also a very good arm.  You could reach out to Bob Graham to ask if he has any 2.2 bearing upgrades. 

I have a VPI TNT Mk2 with a Graham 1.5 arm and Dynavector XX2 MkII cart.  It's a wonderfully musical setup that I intend on keeping for a long while. 

@melm

Thread on a TT is a fascinating audiophile topic on it own. The use of different threads, is similar to using different tubes - different results. I experienced and heard what thread could do with a TNT; but I also saw limitations due to its belt drive design.

Melm - It is well to spray (or soak) the thread with an adhesive.

That sounds kind of yucky to me.
In a TT design that is designed for thread, this is not necessary and it will hurt performance. As an example, with the thread designed original Granito Verdier La Platine; the thread is applied loose and you can in fact flick the thread with your finger as it turns and it does not impact the music delivery.
The remote motor, pulley, platter and bearing design all designed for use with thread.

The 40 number in the previous post was ball park number that I threw out there. I don't remember the actual number, and it was in comparison to that exact thread setup in a thread drive design TT. The message I was trying to get across is that a table designed for belts, if converted to thread, will wear out the thread faster, than a turntable that was designed for thread in the first place. From personal observations this has to do with what is happening at both ends (pulley and platter), the type of contact points, plus the extra tension and slippage that needs to be applied for the belt drive design. 

Personal thread setups do vary greatly especially when extra pulleys are introduced. So to continue a sharing of information here; a picture of your TNT table would be helpful.  

Mike @ VPI, and this is going back many years, told me he used Spider fishing line. I remember this produced "hard sounding" results in my system.

Cheers

I want to thanks everyone for there input,I ended up passing. The reward became minimal to me once it passed the 2k mark,I will keep my classic 1 and be happy :)

"the thread needs to be changed out every 40  records"..My friend never had to change the thread out every 40 records.Last time I talked to him hes never changed anything for over a year of constant playing of records.The guy is a vinyl lover also so he plays hundreds of records a year on his VPI.