I have always wondered why my Dove hi risers were filled at the top, story was it was done on purpose by one of the "bigs", flowed 385, made 785 hp on a 505, and ran high 9's in a Comet. They are cut for T&D's, and came with special head studs for them, and the material left after the T&D cut is very thin, with epoxy fill below, seeming to lower the roof- doesn't make sense to me, other than trying to get a gasket seal, but I would think one could seal it up against the T&D plate at the top? I recently picked up a set of T&Ds but haven't had time to set the plates on the heads for a looksee. Haven't looked at them in a while, maybe they need to go visit the Capt for a looksee/ rethink. They were run on methanol, and looks like the "right" dumdum for meth was not used, as some has eroded anyway. Plan was to run them with my 2-5/8 Kinsler 351C sprint car injectors with a custom-fit Jay-plate when the ports are finished