Headers VS Manifolds
To my knowledge,the exhaust ports on the 273 are around the same size as a 318 head. Much smaller than the exhaust ports of a 340 head.So using the smaller 273 manifolds would not let the motor breath to its full potential,or choke it.
PS: Never pay $200.00 for a mini-starter...$25.00 max at a junkyard.My last one cost me $12.00.
Thats to bad you cant get those 340 manifolds to fit,those would be the ticket.
Seems I have seen them on early A's ?