46callaway
Registered
I found out today the 97/98 Mark VIII engines come with the Cobra high output oil pump versus the standard 2V GT oil pump in the 93-96 Mark VIII...
This is false. I have put the 13mm billet oil pump gears in 93-95 mark VIII oil pumps.
So....for us to understand better, you could have said "all M8s come with the high output cobra pump" or "I have installed the cobra pump in the gen1s because this is what they come with stock" instead of describing the size of the gears because we were all lost on that one.
Here is another poster from the Modular Depot who confirms the early Mark VIII's had the GT oil pump:
"I have 2 Mark VIII pickups here, GT (early) and HO (later). The early GT style tube has an OD of 0.825" and the later HO has an OD of 0.955" They both have the same crank scrapers, and they will only bolt up to the matching pump. The early GT is a duplicate of a stock Tbird/Cougar pickup with the scraper brazed on.
The early MarkVIII had 12mm pumps, I know because I have one."
You cannot physically install 13mm wide gears in a 12mm case and have the proper clearance. So if 13mm billit gears fit in a stock mark VIII oilpump case it must be a 13mm oilpump. Also if you stick 12mm gears in a 13mm case you will have WAY more than the .002" tolerance required.
All 4.6's came with the 13mm pumps due to the extra oiling capacity needed in the valvetrain.
Holly crap, when I just started to read this thread today I thought Joe had surfaced after all this time, then I read the date of his posts.