H2 supercharged transmission upgrade

[medihummer]

my H2 is supercharged. Does anybody have an idea for a transmission upgrade?

the 4L80 upgrade is ni good because I put on 37 inch wheels and the 4L80 is stronger but the gears are about 10 % longer than the stock 4L65. The 4L65 and 4.1 final gear is already way too long for nice performance. I can drive in first gear about 120km/hour which is of course no good for nice acceleration. In fact I hardly need the 3 other gears for the moment.

I went to Geiger cars in Munchen but they had no solution for me except changing transmission every 3000 miles.

I hope someone can help me out