The one in the core support most definitely WAS a factory installed part, especially on the '91-'93 Intercooled trucks.

The optional one was the under-bed mounted version, which is actually dealer installed only.
Just like the tachometers in these trucks all were.

Mark.

 

Ahh. I didn't realise there were differing mounting positions. Thanks Mark! I apologise for my misinformaion.

 

what kind of pressure will the plastic tanks hold? I just bought one thinkin it was the all aluminum and find out when I get it its got the plastic tanks I'm getting around 35 pounds right now but high egt way too quick

 

50 and under. You'll be fine

 

well at least its worth putting in for now anyway thanks red