4~7s is market rate and a good deal for 340 manifolds.
go price out a set of headers and even some cheapies are gonna run you 3~4 easy money, then tack on coating which even the absolute cheapest job is gonna be *pulls number out of thin air* let's say 3 hundy.
or you buy two cans of VHT and pull and paint them every few years.
(this is the part where you say you can buy chevy or ford small block headers that are coated for $10 and a burrito-- feel free to copy and paste this in your response)
