OBS PSD in a E99

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Oct 3, 2018 | 05:32 AM

udsuth78

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From: Ponca City, OK

OBS PSD in a E99

i got the news yesterday that the 7.3 in my E99 is bad. I've been looking around at my options and I think I'm just going to get a used motor to just get it back on the road ASAP. this is my work truck so the down time is killing me. so my question is how much would I need to change if I were to use a 7.3 from an OBS PSD. so far I've found that I'd need the intercooler stuff, fuel system, and injectors from the E99. is that correct and are there any other parts i'll need or want to swap? thanks for any input

Oct 3, 2018 | 07:43 AM

Tugly

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From: Puget Sound

You need to cover the hole for the original fuel pump cam, but that's minor. The driver side exhaust manifold is different, so that has to be swapped/replaced. The intake plenums are 2" on an OBS. I have a 2000, so I bought 3" 8-bolt plenums from Riffraff Diesel. Older OBS engines have 8-bolt intake plenums, where the later engines (including SD) have 10-bolt. The oil pickup is different between the OBS and the SD - but I don't know if you need to change anything if you change the oil pan. The HPOP is different in a big way, so you want to keep the SD HPOP. The OBS UVCH is 2 connectors per head, where the SD has 1 each.

Oct 3, 2018 | 08:04 AM

z31freakify

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From: Las Cruces New Mexico

Just use the OBS long block and install everything from your E99, and plug the hole where the old pump on the OBS was.

Oct 3, 2018 | 09:02 AM

duck fan

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From: Monterey Bay, CA

What year OBS as there are differences between them.

Oct 3, 2018 | 10:55 AM

udsuth78

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From: Ponca City, OK

I've seen a 96 and a 97 on Craigslist but haven't called about them yet. The 96 is complete with supposedly only 125k for 1500

Oct 3, 2018 | 01:12 PM

Bonanza35

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From: Norco,CA

Whats wrong with the old motor?

Oct 4, 2018 | 05:37 AM

udsuth78

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From: Ponca City, OK

compression in the #5 & #7 is bad. (160 & 260) the rest aren't great either low to mid 300s. I had the shop hook the cylinders up to shop air and it was blowing right through to the crankcase. this is my work truck and I need it on the road ASAP so just dropping in another motor seems like the quickest option. I plan to open up the bad motor later to see what happened and see if its rebuildable. having a fresh motor waiting on a stand is never a bad idea in my book.