I want to remove both park bench bumpers on my '77. Maybe find some good 240 bumpers. Possibly new wheels & tires. More than likely new exhaust. And if I'm lucky, some minor body work & new paint. Since I got the heater core & valve replaced, just enjoying heated driving without foggy windows or that oh-not-so pleasant antifreeze scent!!!!
If you remove the glove box, unplug the 2 wire plugs, and remove the heater fan assembly (3 bolts), you will have easier access to view and remove the heater core valve. If that doesn't appear to be leaking, then by removing it, you can access the heater core cover, and slide the heater core out. I just did this on my '77. Alot easier than removing the center console and removing the entire heater box assembly.
I have used Fram oil fitlers in all my rigs for years. My '77 280Z, no probs. My '99 Ford F250 Super Duty 7.3L turbo diesel, which I use to pull a 4 horse trailer (12,000 lbs loaded) not to mention the weight of the truck (probably over 9,000 lbs)... no probs. I guess it's kinda like the old wive's tale about not using Pennzoil. I personally don't use Pennzoil, but if it's good enough for NASCAR, then I don't think there's any problem with it. I would draw the line on Walmart generic oil & filters...........