I installed the Steeda pullies and TA and as a combination they work extremely well. With 14 degrees of timing, the car has alot more low end pull. If I could take a guess, I'd say a easy 10rwhp and 15rwtq. As a side note: A pwr programmer only allows 2 degrees of advance. With the Steeda TA, u can do whatever you want with it. Also, here in Canada I don't know if we have better gas or maybe the weatehr hasn't got hot enough but I run 13 degrees of timing on 87 octane with no pinging. Makes me wonder if 10 degrees from the factory is accurate. I now get better milage too. Go figure.
A while back i want to have my car dyno. I forgot the T/A was set at 10 for nitrous and made 243 rwhp. I then bumped it to about 16 and made 254 rwhp. Both runs made within 15 minutes of eachother. I can remember what the tq. was but i do know it was over 10.
You feel it most on the bottom end. Much more tq. down low. I cant feel any difference at WOT above 4000 between 10 and 16.