Went over to WalMart after work and picked up the EverStart Maxx. Date code on the sticker was 12/16 and I couldn't find any imprints in the plastic other than "L6K" And two other letters after that I don't remember. Is that somehow the date code of manufacture or would there be another somewhere? That was on the top rim of battery opposite the negative terminal.

Went ahead and installed it and car fired up like a champ. That seems to have been the issue. I'll go pick up my old batter from Oreily tomorrow and turn it in to refund my core charge.

Going to have to look into the vents though. I installed the plug in the vent on the firewall side. For the other side, I'll have to call around to see if I can find one of the vent traps or a tube kit to vent it out. 90% sure that the old one has never had a vent but didn't look like the battery tray or under it had any corrosion.

Thanks so much for the help as usual.