I'm in the same boat as you guy. I have my viper GTS coupe my Mercedes e55 amg e63 conv. I like to play haven't gotten as far as you yet. Only got 1000 miles on the C. But it's Cummin.....Soon. I'm with you. Not my first go round with these trucks. The way your set up now I can't imagine why your not slipping in second. And whatever you do beware the 6 -5 drop. You'll loose it for sure there. I'm going re max.my trans is fine.

I'm going to an insurance auction and buying a truck C O D..... Certificate of destruction. They sell cheap. I'm going to use the trans for a core. Keep the engine for a build and sell the parts leftover for more than I paid for the entire truck.

Clutches are weak in the 68....So is the sprag.... Pull your good trans. Save it for a rainy day. Use a POS for a core.