You should be able to get into the 1900-2000 FPS range using H4895 powder.
As far as converting over take a look at the bullets, generally lead will produce less pressure than the same weight jacked round because it offers less resistance down the barrel. Though this is a generalization, you must look at the actual shape of the bullets and compare. The more bullet in the case, the less powder capacity there is and thus higher pressures.
Judging from the reloading stuff from the Hodgdon website (for a 350gr Hornady RN bullet), I don't think you'd be able to stick enough H4895 in the case with a 362gr LFNGC bullet to blow the gun up. H4895 is a bit on the slower side and the pressure curve seems to be pretty modest. Though this is just a guess, don't take my word for it, I'm not an expert don't claim to be. Just getting my info from casual observation of the data; start at the starting load and work up checking the whole way through.
