Check reviews for batteries online if possible. Any advice I would give you would be based on what I can buy here in Canada and wouldn't be much use to you. The Battery has to be rated for your car which all battery retailers could look up if their info goes back far enough.
I bought the car in Alberta and 1 year later, I bought a parts Wildcat also in Alberta and drove down to strip it of parts and brought the parts home to Montreal. Not much left in Montreal for parts. Shipping, duty and dollar exchange means I try to shop in Canada if possible.
Welcome Charles, Lots of good information here when you need advice. In Montreal now, but miss the Pacific Northwest! Love Oregon and Portland! Try to score a shop manual for the car. Makes life easier.
Gary (1968 Wildcat)
Could it be possible that you are overfilling the rad? There needs to be room for the coolant to expand when the car warms up. Several quarts does sound like a lot though. You could also remove the plugs and look for one with a very white porcelain tip. that would indicate head gasket...
I second that. On my 68 wildcat, the battery would discharge slowly when parked. Traced it to a faulty regulator. Unplug the
regulator, no more drain. Went with a 90 amp alt with a built in reg. Been great ever since.
Sadly, I have to let my Wildcat go as my priorities have changed. Here's a link to the KIJIJI ad. Feel free to ask any questions you might have about the car. probably not possible to ship to the states during Covid, but I have not verified that.