I am new to the world of non-adjustible rockers and I need to order new pushrods. My new cam has a bigger diameter and the rocker is not centered on the valve. I have been told that I should messure the needed lenght with a lifter that is pumped up and then add .080 to keep the valves from making noise. Any thoughts on this? Thank you

are these for a flat tappet or roller cam?

if you're using magnum roller lifters, mine only have ~ .060" of travel in them, so the advice given wouldn't work so hot (the valves would hang open). I'd say measure and add .020" or so....

Its a 03 roller lifter. I have not checked the amount of movement in the lifter. I was told at .060 the lifter would make noise, so I should go .080

I'd take that lifter, shim or put a spring into it to get 0 travel, measure, and then add ~ .020 if it were me.

my combo: stock '86 short block, stock mag lifters, mag heads uncut, but valves sunk ~ .020-.030 to increase installed height, stock mag rockers, .028" Mr. gasket head gaskets, and I lucked out, stock magnum pushrods worked out fine. I also picked up a set of comps for a 302 ford, which were like $26 from summit, and .026" longer than stock magnums, and those work also....