Q.....how efficient do you think my torque convertor is....

my last outing at the track i was crossing the finish line just at 5900- 6000 rpms at 104- 104.41 mph with my car in second gear (1.52 ratio) and with my 2.73 gears....running on my street tires that are 245/60-15.....the convertor is a 150 dollar unit from big end convertors also known as TSI........it is a 12" design that is rated from 2400 to 2800 rpm stall.....

it use to brake stall at 2800 rpms in the drive way but now since the head work was done i lost some low end grunt and it stall at the best maybe 2600 rpms but 2500 is pretty easy to achieve.........this is with the motor floored with my brakes pushed hard and no tire spinning.......

Look at the TCI calculators for the info.
You need the tire size though.

http://www.tciauto.com/tech_info/calculators.htm#4

With no slip you should be at about 5370. At 5950 through the lights, that's about 10% (9.7%) slippage.

I used 26.6 for tire diameter, 4.15 (2.73*1.52) for the gear ratio, and 104 mph.