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difference in HPOP b/t years

997 Views 5 Replies 4 Participants Last post by  Patrick Feeley
What’s the difference in with 95 f-350 hpop and 99-03… I see the 94-95 has a check valve and the later models don’t , can the late 99 work in the 95 motor?
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In short, you'll have oil drain-back issues causing hard extended starts using a 99 pump on a 95. I can't recall when the later pumps went to a 17 degree design (flows more oil). The IPR will also be different as well as the front cover. See the attached. Cheers!
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I believe the higher capacity 17 degree pump was on the 99.5 models which went to slightly more injector capacity over the early 99's.

Also front covers are not easlly interchangeable between OBS and Superduty engines. A major difference is the location of the pickup tube changed sides. Passenger side on Superduty front covers.
Thinking you can get a high capacity aftermarket 95 HPOP from some vendors though… please correct if I’m mistaken, without having to retrofit front engine cover.
Thinking you can get a high capacity aftermarket 95 HPOP from some vendors though… please correct if I’m mistaken, without having to retrofit front engine cover.
I don't think there are any problems with bolting a later model HPOP on an OBS engine.
There were a few front cover changes during the 99-03 7.3Ls, one being a change to add an inlet screen in the HPOP reservoir as part of the gasket. The front cover was modified to fit the gasket with screen.
If you try to put a later non-checkvalved bodoed HPOP on a 95, it will have drainback issues, causing longer and harder starts. There are some vendors that have higher output (17* or other) pumps using an early HPOP body to alleviate the drainback problem. Cheers!
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