Need new sway bar bushings, I have a digital caliper, however the sway bar where the bushings mount is egg shaped measuring 34.5mm X 37.5mm... elsewhere on the swaybar is measures 36mm... is there a definitive spot as to where you should measure the sway bar diameter?

88 GTA w/ WS6 suspension

 

The place where the bushings go. After all, you're trying to buy bushings, no? And they have to fit just there, no?

Buy the next smaller size than your measurement. Often, you'll measure in metric, but buy in SAE, or vice-versa. For example, you measure 36mm, that's 1.4173", which is just smaller than 1-7/16"; so, buy 1-3/8". Grease em up liberally and renew the greeeeeeze often.