273 stock coil location hitting vacuum advance

The correct position for the intermediate shaft is with the slot pointing towards the front most intake bolt on the driver's side when the engine is at TDC on #1. So, I would bring it to TDC on #1, pull the distributor and look at the intermediate shaft and see if it's in correctly. If it is, then Bewy is right with his point about that vacuum canister. They are bigger than the standard vacuum canister and I don't think the 273 came with that adjustable vacuum canister. So you can either move the intermediate shaft or shift the plug wires around. Whichever you want.