you would think all the money spent on thease marine headers the engineers would give you a little extra room arounf the tubes to make the job go easier..i usuallly take out the easy ones first and leave the ones in the fromt and back in with a few threads in the head,then work the tight ones and the header will move with the bolt as its be removed..
That's how I do it, I loosen all the stud mounted nuts, then go for the tight Allen heads. Wiggling the header helps get those little allens out. I agree on that design issue too! Wtf.