727 auto to LA small block issues

I haven't ran the new motor or new torque converter at all yet . Luckily I only had the short block bolted to bellhousing and motor mounts. I pulled the engine back out while I have a floor jack holding up the transmission while It's still bolted up. I inspected the torque converter out of the transmission on to the back of the 318 motor and notice that there's a flat metal Ridge that goes around the outside of the torque converter snout in the middle ? It is a couple hairs wider then the inner diameter of the snout hole on the 318 causing resistance? went and got the 360 crank and the snout of the converter engaged just fine into the snout hole of the crank. The 727 was in my truck so I believe it to be 1982 the year of my truck ? Here is The numbers on The tranny: pk4039537 5871 2973 . The motor is a 1985 car motor 482330 that 8 might be a 3 ?