just about all of Dangerboys stack heights are below 30, I have an SR71 that is aobut 27mm.
My Demolition F1 and Coalition Povah (both bmx) are 1.25", which seems to be the common number for front load BMX stems, probably same with all S&M ******* ripoffs and alternatives... But, like evil4bc was saying, top load stems might be lower stack, like the ******* XLT, etc..
And that's right, the SIC is very low stack! I've only had a 1.5 classic from them and i don't remember the numbers, but remember that I had a LOT of extra steerer tube to space out and 1.5 spacers are rare to come by...