I suppose that would work if you're extra careful about the difference in length between the two types, just use a longer pushrod? I guess that would be easy to tell if the length is off too because there would be too much or too little lash...
Just set up cylinder #1 as if it was a 273... Use the 273 solid lifter, 273 push rod, and 273 adjustable rocker arm and adjust to zero lash... Just do that for the one cylinder to check everything and then put the proper roller parts parts back on when you are done...
The 273 parts will be correct to measure the lobe, a lobe is a lobe, approximately .500" lift and 240 - 300 duration...
