Intake manifold for 225 slant 6

Re throttle cable, I don't know about 1962, but 1964+ cars have provision on the firewall to bolt up the throttle cable used those years w/ V-8 option. But, even if you have that, finding such throttle cables and plates is tough today. Better to consider a universal cable solution from Lokar, or maybe retrofit something from a newer car in the junkyard. Indeed, I saw someone had done that in an early-A in the junkyard a few years ago.

Finding a 2 bbl intake and associated parts (kickdown lever, ...) in a junkyard today would be especially lucky. PicNPull links to Row52 which lets you search all junkyards within xx miles. You are 40 miles from me, and I almost never see any Mopars older than 1985 today, other than vans and trucks. When there is a car, one member here is almost always on it, but he leaves comments on Row52 about condition and what parts are left, which is very helpful. Another option is a 4 bbl aluminum manifold. You see them on ebay regularly and a few years ago someone stumbled on new ones on J.C. Whitney at fantastic price (~$150), but they were snatched up in a day. With 4 bbl, you could use a small 390 cfm Holley, or even fuel injection such as EFI Tech (~$1000).