Plymouth Valiant 61 Manual upgrade query

Sorry, I should have specified this is in a car I'm looking to purchase... From my research they were designated "230" nomenclature, but I'm sure you know better than me!
I guess it's possible as you're in a different country, but here, the A230 didn't appear until late 60s or maybe even 1970 as far as I know. Having said that, if it is indeed an A230, then the A833 4 speed will fit where it is, with the proper bellhousing and clutch linkage, of course. I would endeavor to verify the A230, though.