I have a 336 that was rechambered for 356 rimless, which is nothing but the 358 Win loaded to 356 pressure levels and OAL! The 356 is nothing but the 358 with a rim and with a shorter OAL. Factory 358 cartridges won't work through the 336 action as they are to long, but if OAL is kept at the limit of the 356 it works slick. The 356 works at around 52,000 CUP and the Marlin action will handle it fine. There was some talk at one time about Marlin using a special heat treat on the 336 ER actions in which the 356 was chambered, But I talked to a retired Marlin employee several years ago when I designed a wilcat on the 336 about a special heat treat and he said there never was one, all tha actions get the same treatment!
Just use flatnose bullets keep OAL and pressures the same as on the 356 and the 356rimless/ 358 Win will work fine!