A general rule of thumb--------put it where it starts runs the best---then remove cap, mark where the rotor and/or module splines are, remove dist hold down clamp, raise the dist STRAIGHT up with out any twisting of the housing (the rotor will turn some as it comes up the cam gear),rotate the whole dist/rotoer together as a unit to rotate the advance meck away from the thermosat housing(I'm assuming that's what interfering now?)to where you want it to be, push the dist housing straight down(the rotor will turn back towards the mark)((you may have to turn the rotor (gear?) a couple (not much)degrees to start the gear teeth mesh)) and once its down as far as you can push if its now all the way you may have to bump the starter to get it to turn and line up with oil pump drive. Snug it down but leave it just loose enough that you can twist it and then try starting the engine---if need be that the dist is once again not where you want it, do over---once its where you like the looks of it, check the timing with a light-------I used to run 38* total and to check that, vacume advance hose off and carb line plugged, rev eng up til advance won't go anymore and adjust toprobably 36 with todays gas---, then check base(idle) timing--depending on the dist advance slots, should be 10-12 degrees--maybe more/less