AA adapter
I got an AA adapter many years ago, long before I'd heard of plate adapters. Actually, it was long before I learned how to do this work myself and actually paid a shop to do the SM420 install for me. I think now that I probably could do a better job myself than the shop did, especially since I've changed most of that work myself over the years.
There is a pad on the AA adapter that can be used with a Chevtytranny mount to hold up the unit. The adapter is something like 4.5" long, thus is near the limit of the reach on the speedo and the P-brake cables. It also means something must be fabbed up for the T-case linkage to span the extra distance. In my installation, I must remove the adapter with the t-case, as the length of the adapter put the t-case too far to the rear to clear the body sheetmetal , the shafy is still in the adapter when there's no more rearward motion available. Only a problem when you don't know it.
I've had original adapter replaced at no charge by Advanced Adapters due to cracking, the newer one had many strengthening ribs in the casting that weren't on the original. My part number will also work for a certain Jeep combo (Dana 20 I think??) so there's a slightly wider set of customers for it, should I ever try and sell it off. The length of the adapter also puts the front driveshaft u-joint adjacent to the SM420 case, which required grinding for clearance- it seems to me this wouldn't be an issue with a shorter adapter.
If I knew then what I know now I think I'd try a plate adapter - although it seems as if the many various suppliers seem to come and go - the first one I became aware of was Wardens, and then Spaceghost..... AA is still in business - of which I was glad when I had a problem 5 years after the original install. The original job was maybe 12 years ago.
