You're going to get a million diff. responses on which shop to go to. Just do some research, ask around, and call each one and deal with who you feel comfortable with. I've personally had very good experiences with Need 4 Speed and Coastal.

As for gears, I'd def. say 373 as well especially with a power adder and what else you want to do....and the fact that you already have traction probs on street tires.

 

coastal installs and they do outstanding work

 

The stock block can handle it just fine but you probably want to upgrade your injectors for some additional fuel. The stockers can handle over 500 HP. It's not the HP that cracks them but high HP at high RPMs. Keep yhe revs between 5500 and 6000 and you should be just fine. In order to do that, you will need gears and some good torque. I would go 3.73 tops. That's what I had on my '91 with a Vortech S trim and the 2.95 pulley. I would run out of gear right at the finish line in the 1/4 running a 28" tire. Got an 11.0 out of it. Personally, I'd go with 3:55's and pay attention to the torque numbers rather than the HP numbers. Geta a good tune and maybe a chip...and lots of good gas.