Hydralic lifters with rockers vs mechanical

I'm confused.................

you are not changing lifters? Just the rocker arms?

Here's the deal

You cannot swap solid lifters onto a hydraulic camshaft

You CAN use ADJUSTABLE 273 rockers with a hydraulic cam and lifters, but you'll have to scare up different pushrods because the original mechanical lifters are a different HEIGHT than are hydraulic lifters.

If you are running a big performance cam it might make some difference. If there is reason to believe the original hydraulic setup is "out of spec" you might make some difference.

This would come from an improper valve job, IE improper valve stem height, from milled deck and or heads, and to a minor degree, head gasket thickness