first hand my friend. i have personally fitting them to a honda b4 and had no problems. i've also used them in a number of other 4, 6 , and 8 cylinder cars. i have also seen there spray patten up against xxx brand and seen no difference. We all have our own opinions on how things "should" be done. They have worked for me and other people over here without any problems.
Regards Andrew.

but to get back on track, i stand by my opinion and say 550cc wheather they are from a rotor or not for a setup running a T28BB.