i have a bare spindles on a car i bought, cant tell wether they are disc brake or drum-how can you tell-i though the boss at the top where the large bolt goes was shorter, but don have anything to compare with

Yes, the boss is shorter than on a drum spindle. If it measures 3/4" as in the picture, it's a disc spindle.

http://www.chevelles.com/showroom/data/516/medium/Disc_spindle_dim.jpg

great pic-thanks-i wonder if a stock spindle can be milled down or is it spaced diff also
thanks again, i have drum spindles it looks like

Cutting off the upper boss is a common part of older disc brake conversions. I made a fixture that I use for mine.