B&M Hole Shot 2400??
I had Frank Lupo build the converter in my Cuda, way back in the 90's. it was $600 even back then but worth every penny!
I just put a TCI Breakaway in my GTX and boy can I feel the difference over the stock one! Yea, the motor is stock, but the converter was brand new and I got it for $25 so I didn't think I could lose!!
Do as mentioned above, have your converter built! Geof