'87 Suburban 2500 w/ Aux Oil Cooler - Fitting Size?

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bofh

Junior Member
Joined
Oct 20, 2024
Posts
2
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Location
Texas
First Name
Mikhail
Truck Year
1987
Truck Model
Suburban R20
Engine Size
454
I have a 1987 GMC Suburban 2500 w/ 454 in it and well looks like the oil cooler lines are leaking on it. I’d like to run 8 AN steel braided hose instead of seeking out Dorman or Sunsong oil lines. I already have the hose and it's just a matter of getting the right fittings.

It has an auxiliary oil cooler and the lines run from the sandwich between the block and oil filter. Now I could delete the cooler set-up but I’d like to keep it. Mark IV - L19 motor.

Does anyone know what size fittings does the sandwich and the oil cooler itself take?

I keep hearing conflicting info - some on the forums say 3/4-16 x 3/8-18 others say that it’s 3/4-18. I’ve seen people say that it takes 1/2 NPT, 1/2 NPT Inverted Flare.

Any help would be appreciated as I don’t feel like taking it apart unless I have to before I have the parts. Thanks all!
 

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