Firstly the car feels like its bottoming out the suspension on tiny bumps in the road. The previous owner decided to cut the springs

Would it be more cost effective to find used stock springs or get some sort of after market spring? The car has a 327 SBC so its a bit heavier on the front end. What would you recommend?

Secondly, at freeway speeds it has a nasty shimmy that is bad enough that I avoid the freeway. What could cause this? Bent wheel? crappy cut springs? Bad alignment?

Thirdly, Will a 16x7.5 +22, 16x8.5 +37 set of wheels fit underneath the fenders? I have ZGs that came with the car, along with holes in my rear quarters

Thanks for your time,

Jake

Im all ears

Start with new aftermarket springs and struts then have all four tires ballanced. Then see where you're at.

just for starters, Anyone else want to chip in?

Dave.

Secondly, at freeway speeds it has a nasty shimmy that is bad enough that I avoid the freeway. What could cause this? Bent wheel? crappy cut springs? Bad alignment?

Bad tie rods (outer and/or inner), steering coupler, ball joints, steering rack, steering rack bushings, front control arm bushings could cause a shimmy.

Thirdly, Will a 16x7.5 +22, 16x8.5 +37 set of wheels fit underneath the fenders? I have ZGs that came with the car, along with holes in my rear quarters

Not without spacers. The stock offset is 0, however, the maximum backspacing you can have without rubbing the strut housing is 4 to 4.5 inches. The 16x7.5 +22 will have a backspacing of 7.5/2 + 22/25.4 = 4.6 inches; the 16x8.5 +37 is even worse with a backspacing of 8.5/2 + 37/25.4 = 5.7 inches.