Quote Originally Posted by donf View Post
Thanks for the heads up. The converter has been changed to a recent 3" but it has a few goobers stuck to the bed. It may get left off for now, to be replaced in the future. No bathtub pistons, the standard ones that all light duty vans have. No ridge and very little carbon build up. My van is 800 lbs short of the heavy duty GVW. I found it has a replacement passenger side exhaust manifold made in China. The front port has the entire top half blocked off with some excess iron.
I just read back all 5 pages. I forgot you mentioned that the cat had been replaced. That exhaust manifold sounds like a junky dorman replacement. I am not a fan of having those cast iron heat sinks dumping heat into my cylinder heads but they are simple and usually reliable. You might be able to port out the casted shut part without hurting the integrity of the manifold. With the standard pistons you should be in the 9.3 to 9.5 range when you use the thin gasket.