70 TH400 ring gear teeth ... How Many ?

[Bill Kaufman CLC# 15225]

I was having chronic starter problems (dragging when warm) on my 70 Deville. I  took the great advice that I found on our CLC forum and investigated and corrected all the obvious culprits such as timing, Proper Grounds ETC...but to no avail so I decided to go the new Powermaster starter route as some of you have done. The Starter that Powermaster recommended was PN 3631 which is a 153 tooth starter for the early big block Cadillacs , 472 being one of them. I installed the new starter per instructions and it worked for about 20 starts then decided to make a horrible high pitch grinding noise and has obviously binded and will not crank. Finally My question is ..   after some research I found that the 70 472 TH400 setup had a 168 tooth ring gear.. another source says 166 T, and yet another says 153.How many teeth are on a stock 1970 472-TH400 and is Powermaster selling universal starters ? The starter they are selling for a big block Caddies are also being sold to work on many other engines. Which Part Number PowerMaster starter have other people on this forum used ?? Should this #3631 153 T work on my car. Thanks for reading this long post. Thanks for your help.