As far as the bypass valve goes, as I have said all along, you can deal with the issues that are present because of the Vintage Air solenoid valve by just being aware of the issue and managing the A/C use appropriately. The Heater Bypass Valve upgrade kit just makes it a no brainer.
As for the header tank, I am not going to claim that it is an absolute must have. Instead, I would suggest that you do an internet search on the proper way to construct a vehicle cooling system, and then ask yourself if the way the GTM is designed is proper. I have known more than a couple people now that have said they didn't have any issues for quite some time, and then, one day, while out driving, they did. I have also had ONE person now report to me that they STILL had an overheating issue after installing the header tank upgrade.
Point is that it won't cure everything, but it does put things in places that are more of a standard in the industry as far as layout.
In both cases, I would say that it is more of a convenience and "forget about it" type of thing where you may or may not have issues "down the road" if you don't do these things, but as they are much easier to do while building the car, and relatively cheap, many builders do indeed choose to do these "upgrades" just so that they don't have to remember the sequence of A/C control inputs or so they don't need to worry about using a vacuum cleaner to make their cooling system work should they have an issue somewhere out on the road.
As for the header tank, I am not going to claim that it is an absolute must have. Instead, I would suggest that you do an internet search on the proper way to construct a vehicle cooling system, and then ask yourself if the way the GTM is designed is proper. I have known more than a couple people now that have said they didn't have any issues for quite some time, and then, one day, while out driving, they did. I have also had ONE person now report to me that they STILL had an overheating issue after installing the header tank upgrade.
Point is that it won't cure everything, but it does put things in places that are more of a standard in the industry as far as layout.
In both cases, I would say that it is more of a convenience and "forget about it" type of thing where you may or may not have issues "down the road" if you don't do these things, but as they are much easier to do while building the car, and relatively cheap, many builders do indeed choose to do these "upgrades" just so that they don't have to remember the sequence of A/C control inputs or so they don't need to worry about using a vacuum cleaner to make their cooling system work should they have an issue somewhere out on the road.
