225 Air cleaner to carb spacer missing?

Your gasket is old, dry, stretched, and twisted...

Get a new gasket for the carb to air cleaner base...

Also you have a white cap on a vent, I think the vent should be left open, not capped off...

It also looks like there may be a few vacuum nipples left open and may need to be capped.... Vacuum leaks will cause sluggish performance and bad fuel economy....

Thanks. I'll check on the gasket. Something substantially thicker would be needed to get the air cleaner base to clear the top of the carb. Pic #2 shows this the best. I can only find a 68 Plymouth manual and there is nothing in that to give me a clue.....