The height looks OK- - - -the capacity is a bit on the skimpy side. I like an overflow tank with a couple of quarts capacity- - - -with about a pint in it cold to be sure the siphon tube stays submerged. If the original cooling system was a "zero pressure" type, 7 pounds might put a bit of stress on the solder joints at the radiator tanks and the heater core connections. 7 pounds will allow the coolant to stay liquid up to 233 degrees at sea level- - - -much hotter than most stovebolters like to run their engines. Each pound of pressure raises the boiling point by 3 degrees. That's why food cooks faster in a pressure cooker- - - -the internal temp in a 15# pressure pot gets to 250+ degrees.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!