I have an 88 GT hatchback. In the near future, I will be switching to a 5-lug conversion.  Here is my question.  I like the deep dish bullits, and want to go with the biggest wheel tire combo I can without having to modify my wheel wells.  Will 18x10's do the trick in the back, or is the 18x9 combo the widest I can go.  In addition, can I do the 18x9 deep dish bullitt ont he front.  I have seen some pics of the bullitts on the fox body stangs, but of course there is no telling what mods they had to do to get them to fit.  Am I being to optimistic with the 18 series wheels, or should I just stick to 17's.  Thanks in advance for the help.

On our wheel and tire kits, the 18" and 17" kits have the same overall rolling diameter as each other.  With the size of wheel and tire kit you are wanting to run, and depending on if your car is lowered, you will more than likely have to modify things to fit.  I have a WTK-1007SCU on my 92 LX hatch that has been lowered and I had to Roll all 4 fender lips so they wouldn't cut into the tires.  Now the rears are rubbing on the exhaust so I have to modify that now.  Your best bet is to go with 9's all the way around.  It will save you some headache if you don't want to modify much.

Thanks for the info. I guess I should have also added I would be replacing the springs too.  Probably going with a slight lowering spring kit such as the Eibach Pro Kit or the H&R's with a slight drop in ride height.  I will probably stick with the 9's just to keep things simple.

I specifically bought a 5-lug, 4 wheel disc brake kit so that I could install black 17x8 bullitt wheels on my lowered 1990 LX. Problem is that I bought the SSBC A112-2 kit that uses SVO style front rotors and (of course) 5 days after I ordered the kit I read that these wheels won't work with my brake kit. In fact it looks like a lot of wheels won't work because of the larger center hub. What options do I have? I am hoping I don't have to return the kit but it looks like that may be the best thing to do as using this type of setup will limit my wheel choices (which is why I want to convert to 5 lugs in the first place!).

You are correct, using the SVO style 5 lug conversion kit will limit your wheel choices.  The only wheels you will be able to use with those are the 95 Cobra R style wheels, 94-97 cobra wheels, 94-95 17" GT wheels "tri-bars" 94-98 16" gt/V6 wheels "waffle wheels", 17" Pony R's, weld Pro-Stars/Drag Lites etc.  You won't be able to use the wheels that came on the newer cars such as the Bullitt Wheels, FR-500, 98-04 Cobra wheels, Saleen Style, 10th anniversary Cobras, SVE wheels, etc.  The only way to use those wheels is to use the more expensive SN-95 front 5 lug conversion set up.