unfortunalty you cant boil those tanks. but you can have it flushed out, any pin holes repaired, and red leaded
you should get another 20 yrs out of it. I did mine in 91 and so far so good but it is past its usuful life and id liek to replace it.
every now and then one pops up on ebay for $200 but youll never know what theyre sending you. yours may end up being in better shape
if you want to vent your cap you can just drill a little 1/16 hole in the inside base and leave it as is.
1970 Mach 1 San Jose built Dec 23 1969. Marti says 1 of 7. Purchased in 1987. Original family owner of the powertrain 351C 2v FMX.
1993 GT 11,000 miles, Built 2-12-93 Auto, 3:27 Axle, cloth, sunroof. Untouched except for rubber and battery, Purchased new 8-3-93. still has the factory windshield fluid and new car smell.