Same radiator cap works fine with 160 and 180. 0 pressure cap on old radiators(pre-47?) and a low 4-7 for newer say 47 to 58? 15 Lb for 195 to prevent boil over. If you have a good radiator. I have run more modern, say 1967 and up with a 180 no problems, but for systems designed for higher temps, you might run a bit rich, and new stuff has to pass emissions testing, so stick with what the manuf. suggests.
