crown ABF 1`75 super flame issue

hankwylerjr

I have a customer with a ABF 175 LP propane system. I believe that a handyman or homeowner did some work and may have replaced the gas valve with a different model then intended . I replaced the thermo couple cleaned everything replaced the vent pipe. I get a super big blue flame causing soot looks like to much gas is coming into the unit. I checked everything and determined that the spill is bad as I bypassed it and it fired up. This boiler says its nat gas but tag says LP and its old but functions. Tomorrow Im going to cross reference the gas valve with the weird serial number of simply "1212" cbs series I think. Maybe the gas valve which is new is raw wrong one or can it be converted incorrectly for propane? These old boilers I usually can diagnose this ones tricky. The house was just sold I think like I said somebody messed with this and some of the unions and other black pipe where I located a leak in a union and the pipe dope was smeared everywhere a telltale sign someone didn't know what they were doing Ill post pics in a few hours thx in advance