Let me put it this way, you can definately do without the AC and PS. Both units weigh probably a good 50lbs each not including the brackets and etc.. and also the benefits from taking that extra strain off the engine will get you good gains. The car is so light you won't be able to tell it had PS in the first place. Also the 4ACs had the longest final drive at 4.3, GTSs came with 4.5. Valve adjustment isn't hard at all.. just takes a little time and patience to get it right.
Seriously, let me know because I would enjoy getting in on that experiment of yours. We can get the AC and PS out and loop the lines in no time, and I'm sure I could get you a really good deal for valve shims and everything else you might need.
edit*- You can find longer final drives but you're looking upward of 400, which might be a bit more than you wanna drop in that car.