What is an easy break upgrade from stock to improve stopping power (Mainly because these cars stop like cruise ships). currently disk front and drum rear

 

Welcome to TGO.

First thing I would suggest is to make sure your brakes are in good working order. Rubber lines are well known to go bad, and let's face it, these cars are old. Pads, rotors, calipers in good working order....good/new fluid etc. etc. If they ARE up to par, then yeah....even then they're not the best. To my knowledge, the best bang for the buck is the conversion to LS1 era 98-02 -4th gen front brakes. We just call 'em LS1 brakes. I've got em. They fit directly under all 16" thirdgen wheels except the crosslace wheels, and even then a small spacer with give you the clearance you need. You'll need a modified spindle and hub which you can get at FlyNBye performance or Bigbrakeupgrade. I've used FlyNbye for my brake stuff. http://www.flynbye.com/catalog/i47.html -that's for just the custom conversion stuff. You'd still need the brakes themselves. Figure about $750/$800 for the whole turnkey conversion in a nice kit, brakes and all, to your door. .....there are plenty of larger kits, but the LS1 kit is lightyears beyond stock thirdgen stuff, and makes a huge difference.

I see you have a 91 RS. What size wheels do you have? I don't think there are upgrade options for 15" wheels. Well...they do.....they're called 16" wheels, lol.

 

will the ls hubs fit our cars ? direct bolt in ?

 

No. You need modified thirdgen spindles, which will accept 4th gen hubs.

 

You mean 4th gen rotors? Never seen a 3rd gen spindle modified to accept a 4th gen hub

 

Yeah, it's a modified thirdgen spindle, with modified thirdgen hub........stock 4TH GEN rotor. ...and calipers etc.