At 119 mph in the 1/8th, leaving like a pooch that tells me this car is making a lot of power, just not much till the Rs get up over 6500 with that cam? My guess is the REAL 1/8th mile per hour would be 121 if it got moving better early. That would be about a 5.75 in the 1/8th, or 9.0 in the 1/4. The 4.10 gear gives you a SLR of 7.40, and I would think it needs more like 9 or higher for decent results. However, it sounds like it is all three issues pointed out. Not enough gear, wrong converter, and a very big cam for that motor and trans combo.
If it were my car, I would borrow a much shorter cam, somewhere around 280/288/110 like my Isky RR735, get a converter built to stall 6500, and put a 4.88 gear in it.