Working on a 2002 Blazer, 4.3
It had a intake leak, I changed the gaskets. While I was doing this repair the distributor was wrapped in a rag and dropped. It looks fine. But ever since the repair I get a miss shown in the Tach inder load, surge at about 60 mph feels like trans but don't think it is. it is worse in cold weather. I get PO335 code. I have installed new cap, wires, plugs, map, cam hal sensor in dist.I have checked for vacume leaks, fuel leaks. Nothing found.

What do you guys think.

 

I would look close at the distributor drive gear. These love to crack and cause all kinds of weird things to happen.