The Speedmaster site is wrong..
Even more embarrassing about their own head... You don't need oil through pushrods which means you can run solid lifters with adjustable rockers..
Which if you did that you could take your cam and have it ground into whatever you wanted it. Get mechanical lifters.. maybe some 273 rockers which would be inexpensive. Relatively speaking of course.. then of course once all of that is in place you can get a measurement for your pushrods and have Smith Brothers make you a set..
You should be able to get a good set of 273 rockers for under 200.. not sure about the solid lifters.. but if you call Ken at Oregon cam and have him grind your cam it cost me about $79 for the regrind. He may have some lifters for you also. And he will grind you a cam given you give him all the information about your car and what your personal expectations are of it... Not what the Forum thinks you ought to do but what you want...
and the Smith Brothers pushrods used to be about a hundred and thirty-five but now they're just under 200 I think for a custom set.. they will send you a single push rod that you can use as a template and it's adjustable..