I have a pretty good detailed explaination of how to tune a carb with timing. Which should be done together. I looked for it last night on my comp but I think I actually have a hard copy in my 40 folder. I'll see if I can post it up. My 64 blew easily.. I'm sure your 76 shouldn't be a big deal.
See you on the trail
Couple o' FJ40's, BJ70, UZJ100, TDI