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How much lift to put a HP D30 in a Y2K?

N8N_99xj

NAXJA Forum User
I'm pretty sure I either have a bad U-joint or a chipped R&P in my 2000 with a LP D30. How high would I have to boost it to be safe driving it with a HP D30 swapped in? Reason I ask is I also have a low miles 99 that I'm using for parts and it's super solid. Trying to decide if I find chipped teeth if it's cheaper to get a junkyard LP or just boost it and swap in the HP from the '99. I have a 242, 8.25 and no SYE if that makes a difference.
 
I'm pretty sure I either have a bad U-joint or a chipped R&P in my 2000 with a LP D30. How high would I have to boost it to be safe driving it with a HP D30 swapped in? Reason I ask is I also have a low miles 99 that I'm using for parts and it's super solid. Trying to decide if I find chipped teeth if it's cheaper to get a junkyard LP or just boost it and swap in the HP from the '99. I have a 242, 8.25 and no SYE if that makes a difference.

Why not just fix yours? I've been at 5.5" on my LP D30 (2000) now for 17yrs!

AFAIK cali xjs came with the pre cats and the HP 30 in 00, didn't they?

No, they were all LP D30's after 1999.
 
Why not just fix yours? I've been at 5.5" on my LP D30 (2000) now for 17yrs!.

Because I have a good condition HP D30 at my disposal running Redline Heavy Shockproof since 70K miles at my disposal, that's why. LP axle has 255K miles and unknown maintenance, although it's had at least one fluid change based on RTV squishing out.
 
I have a thread asking about this very same question. Some folks are claiming to have interference even at 3.5" and just let it beat the exhaust up. Up Country is about 1" over factory ride height, with different shocks, and deletes the rear sway bar. I have never tried a HP30 in a pre-cat Jeep. I decided to keep the LP30 in mine. I would not get too hung up about the Redline unless you changed it every 12,000-30,000 miles.
 
I changed the gear oil in the HP axle when I got the '99 at about 70K and again maybe 2K miles ago. Just would rather use that than swap in an unknown JY LP D30 if I can do it without too much trouble. Of course it could be the noise in the '00 I'm hearing is just a u-joint or something, I've been pulling half days at work consistently, including at least one weekend day, for the last three weeks straight so I'm too damn tired to even think about driving to the shop much less doing anything. I hope it doesn't grenade until I can address it...
 
OK so if you're at 1.75" with stock non-upcountry springs, a 1" or higher BB should be OK then *with* upcountry? Thinking about it. Still need to get some lift time to find out what the real problem is. How hard do you flog it?
 
OK so if you're at 1.75" with stock non-upcountry springs, a 1" or higher BB should be OK then *with* upcountry? Thinking about it. Still need to get some lift time to find out what the real problem is. How hard do you flog it?

It gets some spirited driving on dirt roads and two tracks. It's been flexed out to the bumpstops without any contact between the axle and exhaust.
 
I have 01 with a hp30 with 4.5 lift no clearance issues, even fully flexed. I think to only way I could get it to hit is with a longer track bar pushing axle to passenger side.
 
I'm in an '01 that has been outfitted with a HP and I do not have any issues. I am currently running 6" of lift with LA's.
 
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