Have any of you guys run TB's 'tall' open letter Cobra valve covers? I have pulled the oe 289 K code/T10 to store it from my '66 and am putting in a 347/T5 combo. I am running a complete roller set up in the 347 and bought the 'tall vc's to clear the roller rockers. When they arrived, they had a note inside telling me I may have to grind off parts of the rocker arm (!

!) and or the inside of the valve cover! They also say maybe remove the 
oil baffle, which I would obviously not like to do. Are these tall enough for most applications? I am running Edelbrock alum. heads w/ Harlan Sharp rockers.
I hope I will be all right with the 'double thick' FelPro gasket #1645 but I would like some input b4 installing these and making them non-returnable.