ive been reading thru some threads and people keep bringing up putting tranny oil in the carbs, ive been needing to put new oil in my su's and i have alot of extra redline tranny fluid, so can i use this or what?

Sure, why not.

If it doesn't work then buy some ATF.

Can't hurt a thing, only performance and ego's!

FWIW, I think tranny oil is heavier weight?

don't use tranny oil (well, gear oil..). it's viscosity is WAY too thick for the application. most gear oils are of the 80W-90 variety, and you should be using 20wt. in your SU's. ATF may work, that stuff's pretty thin... i would goto a parts store and just see if you can find a quart of SAE 20 oil. if they don't have any on the shelf, ask them if they have some in back or if they can order it. might be a hunt nowadays. i havn't seen any 20wt. oil at our local parts stores (and i worked at one) in a while. victoria british and motorsport both sell carb oil, although, i'm not sure how much they sell...

would machine oil work? hmmm..... i dunno...

You can a little 3oz metal squeeze can of 3-in-1 20 weight oil (blue and white color on can) at many places including hardware stores. It's not like you need a whole gallon of the stuff. That's what I've always used and it's what was recommended by Nissan. A quick froogle search turns up this ad with an image:

http://tinyurl.com/95tf