New to Stangnet with a few Q's

Hello StangNet-

I have been reading in this forum for the last year and enjoyed learning more about my car from many your posts. Your experiences and knowledge have enlightned me on many occasions. Three years ago I bought a 1968 mustang GT fastback with a 390 and C6 auto. I'am into performance and I have recently put the original engine on a engine stand and put in a 390 crate motor.
The crate motor makes 425 horse and 450 torque, with the new motor I put on Hooker super comp headers to a 3 inch exhaust to flowmaster mufflers. The C6 has also been upgraded with a Trans-go shift kit and torque converter. The Rear end is 3.50 with Richmond no-slip traction system. The wheels are 17 inch torque thrust II's with 235/45's.
Now to some of my questions that I thought maybe you could help me with:

1. With my current set up what do you think my car is capable of in the quarter mile, haven't gotten it to the track yet? (I was hoping to be in the 12's, if not what will it take?)

2. What is the curb weight of my car? (Engine has aluminum intake and heads also have aluminum radiator besides that no other weight reduction)

3. Is it possible to run 275's in the rear without any major changes to the car?

Thanks to anyone that can answer any of my questions.

Thanks for the replies,

MustangDave-
Ya I was thinking about going with cal tracs and they seem like a good idea to get this car to hook, have you had any experience with them?

Frost-
Thats great I was worried that I was going to be stuck with these 235's.. But a question that comes to my mind is how do they look? (I'm mean do the wheels hang out the side of the car? Or they on the inside looking flush and clean?)