Is this Factory? 307 exhaust headpipe restriction?

[FirstOwner69]

It would be extremely unusual to find an original exhaust system on one of these trucks. Those were the days of leaded gas. In my experience it was normal to replace exhaust systems somewhere around 30,000-40,000 miles if not sooner, especially in cold climates. Not to mention the 10K between tune ups. The heat riser added to that problem since the system would not get dried out on short trips. There have definitely been some advantages to unleaded.