Oil pressure wire

[cubby]

I'm trying to finish my sons 91 suburban. My problem is the Oil pressure wire would normally be tan in color with an offset plug on the end. As it is on all my other Chevys 6 in all. On this 91 suburban harness there is no tan wire or plug. We have installed an 86 Military 6.2 with a mechanical fuel pump on the block. I'm wondering if the 91's had a fuel pump in the tank? Any info would be greatly appreciated.
Total restoration, frame off. ATS turbo. only one I've seen. Vista blue.

[john8662]

Was the 91 Suburban originally a Diesel?

If it was a diesel, it had a mechanical fuel pump just like the 86 engine you're transplanting.

The 91 should still have the single plug for the oil pressure gauge.