Finally, I got the retailer to give me an update on the 3912600 Exhaust Manifold. Cummins is out of them globally. They won't have one available until April 16, 2021. I canceled the order. I am now looking for a good used one.
I connected the fuel lines yesterday as well. I just need to wire the new electronic pump on the frame. (Note:The pump is to be used for priming the fuel system, not for regular running. Although, when I purchased the Grumman van an electronic pump was used for running. I went back to stock.).
Then hit another problem. I ordered another transfer case with a 32 spline input to match the 4L80e transmission output. I needed to do this because the original 700r4 transmission has a 27 spline output and the NP208c transfer case has a matching 27 spline input. The six bolts which connect the transfer case to the adapter are M10x1.5x30. I purchased new bolts (flanged 10.9) to replace the existing bolts (unflanged). I found out that these are not the right bolts for the new NP208c transfer case (Same transfer case as before). Does anyone know if they changed bolt sizes through the years? The M10s do not want to fit.
UPDATE: The bolt size is 3/8-16 course. The bolts (6) are 1-1/4 inches long. Again I ordered flange bolts to increase the area of contact.