Have you checked your ignition coils to make sure they are in spec? I did not see that you changed them. Also are all the pipes hot to tell you they are all firing. I had an issue that mine would run but had no power. It ran on one cylinder as coils were bad.
I was able to find one on eBay. The way you tell is that it has angled rectangular brackets that slide over each other. This is how the 77-78 seats were. The earlier pans from 70-76 were round slots that connected with pins. It's kinda hard to explain but obvious in a picture it I could attach.
Hello. I am trying to find a seat for my 78 model. I looked on ebay and apparently this is a hard to find part. I will buy the whole seat or just a solid pan. Thanks.