Suspension travel question and rear spring rate

[BigBlockOlds]

Okay, here is what I have for a bit of background:

1987 Olds Cutlass Supreme

Front suspension:

SC&C stage II kit
QA1 single adjustable coilover's w/ 550lb/in springs
Stock lower control arms with Del-a-lum bushings
36mm hollow sway bar

Rear suspension:

QA1 single adjustable shocks
Edelbrock double adjustable upper control arms with spherical bearings
Currie-trac lower control arms with spherical bearings and poly bushings
Fays2 watts link
SC&C Pro-tour bar (soon)

With the frame notch I did, I wanted to tie the two sides together a little better and welded in a cross brace that runs from side to side between the upper shock mount and spring pockets. This is then tied into the "dog bone" just in front of the rear housing.
But now I have about 1" less travel as the tops of my upper control arm ears on the rear end hit the new crossmemer.

Height from my lower shock mount to upper shock mount when the rear end is touching the crossmember is 14-14.5". My shocks, fully compressed are 13.5". I have a set of polyurethane bump stops that I was going to add to the new crossmember which are 1.875" tall.

My question is will the 1"-2" less suspension travel hurt me? Will I constantly be hitting the bump stops during normal street driving or occasional track time?

This brings me to my second question, what rear spring rate would be good to match the front suspension? And if this ends up being stiffer than a stock spring, will I have to worry less about bottoming out?

Thanks for the help,