manual vs. auto

[lewisaric]

I am planning to put an ls1 in my 68 short-step 2wd and cant make up my mind on weather to put an automatic or a manual trans behinde it. If I go with an auto I`m gonna use a 4l80, if manual it will be a t-56 six speed. I would rather go manual simply because it is more fun. What I want to know is will I be able to drive the 6speed or will I just burn the tires every time I take off. I have read shifty`s 68 truck build on ls1 tech and everyone seems to belive that, depending on the gearing, either 1st gear will basicaly roast the tires or 6th gear will only be able to be used above 100. Is 6 gears to many for a truck? Or could there be a happy medium in the gearing to utilize all 6 gears.