OEM Springs VS OEM HD Springs??

I am looking at eventually doing a small 2" budget lift on bilsteins, 30s or 31s, and armoring up the bottom of my XJ for light trail duty, but I have one question.... I have 150k on my 98 Classic, and want to replace the springs, which are obviously sagging (my rears are nearly inverted). I am not all that interested in lifting beyond 3" as I want good gas mileage and want all new OEM front parts except maybe track bar, and mainly want it for DD, towing a small uhaul/jetskis, and light offroad work. I have looked for springs, and am finding OEM "Heavy Duty" front and rear springs. How do these differ from the springs that came on my XJ to begin with. It doesn't have the tow package from the factory. My goal is to replace the leaf springs for now and do OME 2" Medium Duty coils in the front (but maybe OEM HD coils in front for now... With Shackles and 1/2" blocks in back with 1" lowered NP231 (eventually) I guess my question is...

If I buy the as advertised "HD" springs, is this going to give me a better spring rate than what came on my truck to begin with? And if you have used them... how do you feel about them?

Thanks..

The "HD" springs came on XJs with the "Up Country" package. I think it gives you about 1" over stock.

i bought the heavy duty rear spring packs from qadratec back in september of last year and they were 2" higher than stock and have not sagged yet

Go with the OME springs they will give you a little more lift the HD ones should not give you more than an inch unless the ones on it now are sagging. I think they are damn near the same price too.

bought my '01 new and it came w/ the "Up Country" suspension. it was a little over an inch higher than a non-Up Country XJ and came with gas charged shocks. it worked fine for 30" tires. however, imho it was a very stiff ride and when i swapped over to the OME Heavy Duty springs, 3" front/rear, the ride improved significantly. of course i also swapped out the stock gas shocks for Rancho RS5000's at the same time....may have affected the ride too. i've had the OMEs on for 4 yrs/55k miles and they are not sagging..and still ride very nicely. at the time i bought the OME springs there was a 2" and 3" set available. my buddy put the 2" OMEs on his TJ and was really happy with the ride. just a reminder...make sure you increase the bump stop length equal to your spring height or you will probly induce some sag due to neg arching.