Apologies in advance for the pictures. :cry:
This is the tank I'm using. Designed to fit in the space under the body on the left side of the car, there is no interference with the ISIS module or the GM ECU. It is also mounted about as high as one can mount such a tank.
The underside view shows the 3/4" and 5/8" barbs to convert the heater hose to the same size on the way to the 4-port heater valve. There are also ports for the steam vents (all 4 of them combine into one AN line) and the rad bleed hose.
The neck has a barb to run to a coolant overflow tank that I still have to design and fab.
The tank fits perfectly and clears the body, the engine and the down-tube from the roll cage. Took a little time and effort to make it just right.
I will wrap it and the bulkhead in gold foil, probably, when it gets to final install.
If I were using the Dorman tank, I'd be sure to mount it as high as possible.
The Canton and other tanks don't have all the connections we need, IMO, which is why this one is on my car..
Well, that, and I like stuff like this.