'92 a518 vss to '97 OBD2, compatible?
the A518 you have is a 46RH that you can control with a kit from PATC
PATC 727 to 518 / 46RH Conversion Kit. Click here for 727 to 46RH swap wiring diagram - PATC
But it will not work with your pcm
Now what you can do is sell the 46r
H and buy another 46r"
E" there are two versions that will work with you computer. Both have a speed sender at the 8 o'clock position, this is what the pcm reads as well at the speedo sender. Here's where it gets tricky. The early 46r"E" had both. This will allow you to run the adapter in your first post. The Later 46r"E" had the speedo sender in the dif and will need to be converted in order to run the speedo in the over drive unit. I'm in the process of converting mine over from a later overdrive housing to a early 46r"E" tail so I can run my speedo as well have my pcm control my trans shifts and lockup torque converter , you can see it in my build thread below. So far cost hasn't been much. $50 for tail housing and gear drives from PATC for about $15-30 that is if all you can find is a later model 46r"E"
1965 Barracuda MMP
The picture below you can see the speed sender but no speedo drive hole "Later" 46RE
This picture you can see both the speed sender and the speedo drive hole "Early" 46RE
There is a third tail housing that has the speedo hole and the casting for the speed sensor but the casting is not drilled or tapped. I'm told its for a 2wd Diesel unit "Early" 46/47RE
Good luck with you build...