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.

[OARNGESI]

My car is a 6 speed and 1st and 5th are pretty much useless not sure in this situation

[TonyJohnson]

It depends on your rear gear. If you've got 4:10s, 1st might be too low. In that case, 6th gear would be a god-send... But if you need to start in 2nd, what's the big deal? Just start in 2nd. Always better to have too many gears than too few. JMO...

Also, unless you're planning to run 600 hp, the 4L80e is overkill and a pain to get setup $$$ without the right ecm/harness/engine combo and some computer skills... A well-built 700R4 will get you to the same place a lot easier and cheaper (unless you're running 600 hp...)

[Tom Vogel]

I have absolutely no idea why you couldnt use a six speed or why Any gear would be useles provided your truck has the correct rear end ratio. Lets reason this out... GM puts these trannies and LS engines in cars and they work great... theyve spent millions researching and in product development... the tranny cant know the difference between a 4000lb. car and a 4000lb truck... sooo...