38x14.5 R20 tires, 20x10 monster xd's
 

Will this set up work with a Rough crountry 5.5" lift and 3" BL? Scrubbing? Backspacing=4.53

They will be too wide, you'll have to add spacers if you don't want them to rub.

From what people say, I don't think that you want to go any bigger than 37" tires on the IFS front axle. They should be fine on a SFA. But yea, you will have some rubbing if you do get them on there.

First off, 10" isn't a big enough rim for the 14.5" wide tires. You'd be squeeeeezing them on.
IFS axles aren't tough enough for tires over 36" unless you go easy on them.
That wide of a tire, with that lift, you should expect not more than 10mpg on the highway.
I would think you need fender flares automatically with a tire that. Bigger is not better in the tire department! Those tires have to weigh almost 80lbs each plus the weight of the wheels themselves. Think of all that rotating mass on the axles and all that weight being thrusted into the shock assembly when going over bumps. Tires this big will tear apart your front end on an IFS truck. Blljoints, tierods, steering box, alignments...etc

I'd go no bigger than a 37" tire and no wider than 13" for the IFS

Yep, they'll scrub and absolute minimum for that tire width is an 11" wide wheel.

For best wheeling performance vs. clearance, you really need to stay with a 35" tire, and for that, you'll still want to re-gear. If you resolve yourself to the fact you will replace front end components faster, then maybe 37x12.5s, but you should not go all suspension lift to clear them, the CV angle will be too high and you'll surely bust one at some point...

do you do any wheeling in your truck? if so ide save up and SAS that beast with 3/4tons and then youll be fine and wont have to worry about IFS anymore

If I only knew in early '04 what I know now!!! I had a '98 2nd Gen 1500, had a solid front axle. Never even gave a thought to the 3rd Gens not having one. I actually went to buy a CTD but they were giving about $8000 off on the 1500s between rebates and dealer discount and not budging a dime on the CTDs, and couldn't justify paying $17,000 more for a truck that stickered for only $9000 more. I should have seen what they would have done on a 2500 Hemi. Oh well, water under the bridge...

20x10 would be fine, I know people with 18x9 with a 38x15.5 R18.
And yes I thought about a SFA, can get one for $700, but I do not have the money to do that+labor+another lift. I was going to do my 38" tires for right now, because all I do is road driving, I do mud some but I will not with my IFS and 38" tires, too much stress.

In about a month or two I'm switching over to solid front axle, and what sucks is I have to change my solid axle in the back with another 2500 due to the bolt patterns, or would that really matter??

I never said the tires wouldn't fit. They just aren't meant to be put on that small of a rim. besides, you cannot compare 18's to 20's because you lose that extra sidewall flex.
I don't get the wholepoint of what you intend to do? WHy put on a 5.5" susp. lift and a 3" body lift with some monserous tires if your never gonna stick the truck in some mud or do any offroading? Just doesn't make sense and seems like a silly DD to me. Just my .02


Also, you just stated that you didn't have the money, but then in a month your gonna be switching over to SFA????? i wouldn't bother if your a pavement queen. It's wasted money.

I gotta disagree with you on one point 'dog, 38s will have plenty of sidewall on a 20" wheel, comparable to 35s on a 17. He just doesn't have the truck to get away with it. On a 2500 that combo would be sweet...