[Vwdiesel] Radiator Parts Help Question

[Val Christian]

Gang,

My 91 Jetta NA, with air conditioning, has a leaking radiator tank.  As
near as I can tell, with the system pressurized to 18#, and cold, it's
three slow leaks from the right side of the tank.

The last radiator I put in was a VW 191 121 253A

I've bought several radiators, all purported to fit, none are right.

Autohauz has a radiator which is a 191 121 253AZ.  Can anyone tell me the
difference between the A and the AZ suffix?

Thanks.

Val