What was done to the front suspension? The big and little tire combination is squirrely on the street....Probably why the trend is going away from Pro Street and more to Pro Touring with some emphasis (finally) being put on making a performance car handle and stop, not just accelerate!

Anyway, to your question. I can see no way the addition of a 'glass front end would have any effect on the front suspension.

I would suggest putting the car on a 4 wheel laser alignment rack and see if the car is straight and square and if the alignment is set correctly. Hopefully the shop that did the tubbing put some attention and upgrades to the front suspension, too. If not, learn to live with squirrely or get some front suspension that is up to keeping a hi horse car straight on the road!!!!!