Ignition timing

Getting a bit of pinning under acceleration, I’m thinking when I had work done on the car it was timed without bypassing the computer. The shop manual shows the location of the bypass but all I can find is a flat plug with two wires. I have the original harness that came with the motor out of a caprice and the bypass on that harness is the typical tan wire plug. I looked online and could only find one instance of confirmation that the double plug I have on my 91 ready is the bypass. When I looked in the harness both wires are tan. Can anyone shed some light. Because even the mechanic that did the engine swap couldn’t find it.

The connector is a 2 wire flat plug, and sits on top of the passenger's side valve cover. I believe you have found the right one.

What year harness do you have on your 91? 92 and 93 harnesses are different from the 91. What engine did you start with, and what do you have now?

I have a 91 roady and the engine that went in was from a 91 caprice. My original harness stayed with the car and the donor is in a box in my garage. That’s great if the flat two wire connector is the bypass. I’ll be able to check the timing now.