Cliff Harris

The reason the oil switch and oil pressure sender are where they are is because that oil passage in the block comes directly from the oil pump. Chevy small blocks have had the oil pressure sender there since 1955.

The thing that puzzles me is the EGR tube over the passenger side valve cover. The old carb heat crossover passage still existed in the heads, but was blocked off in the TPI intake manifold. Seems to me they could have used that for EGR. I guess they had their reasons for doing it the way they did, but still...

Mountaineer

thanks, that explains it. i guess to locate the sending units forward of the distributor where you could actually see and get a wrench on them Chevy would have had to design and install some sort of extended tube or fitting to get the oil to the sending units, and that costs $$. what i did was remove the bell shaped pressure sending unit and install a 1/8 NPT fitting and a 1/8 dia compression fitting and poly tube from Summit to feed the mechanical pressure gage. I have had the same set up in my p-up since 2002 with no leaks ever. on the oil pressure switch i installed a 6" long two wire pigtail to plug into the harness, so at least you can unplug the thing without standing on your head.

Red88Vert

Dumb question, but it was the oil temp switch that you showed in the pics yes?

Stingraynut

It was the oil pressure sender unit