Andy,
You are correct they do look abit steep, but im sure all measurments are correct, as there were no clearance issues when i had the wheels on, regarding up/down travel. I actually put rs14 on first but im sure d11's were cut to 66 degrees as i remember doing them with a hacksaw to get the angle. they may look abit steep due to the fact i made d11 rails out of 32mm box section to give the rear end abit more stregnth. Il get the protractor out in the morning and double check, so dont go crawling under your stone just yet
regards
nathan