360 vs 383

Guys are running larger cams than that on stock roller setups.

How much lift with stock magnum roller lifters?

It's lobe lift you'd want to consider though, not valve lift.
Yup, i just didn't know my lobe lift offhand :) Saw a guy post he's running much more than i am without issue.. so now i know :) Plan to double check next time it's apart...

P.S. i'm only .353 at the lobe, nothing huge.. i just trust the OEM lifters, plus they are cheap so.. win/win