EmTee

Ah, the 'good ol' days! I changed lots of tires using a 20-20 in the mid to late '70s!

Something about that breaker set appears to be bent or broken. I had the arm break in half on a VW beetle 40 years ago. Remove the points from the distributor and get them on the bench where you can inspect them. Also check the breaker plate and inside the distributor for anything that looks like it shouldn't be there.

Now the fun begins!

OK - now you have to repaint the air cleaner housing!

Congratulations - it will be good to see one of these regularly on the forum! As far as the door is concerned, I would remove the inner panel on the 'good' side and study the mechanism. Then you may try 'fishing' with a wire coat hanger to see whether it's possible to trip the latch if you feed it into the door through the window opening. Practice on the one you can see and then try the same technique on the side that won't open. It sounds like a rod has fallen off or something is broken...

How did you adjust the valve lash? Is it possible one or more may be too tight? I'd probably start by setting #1 piston at TDC and measure the cold lash. When I set mine cold I used 0.019" instead of the hot value (0.015"). Roll the motor through the firing order and see whether any were too tight, as those may not be closing completely when hot. At this stage, too loose (within reason) is better than too tight. If the valves are quiet now I'd be suspicious that they may be too tight. If you do see a number of valves too tight at the TDC for each piston, pay attention to which valve (I or E). If it looks like all of one type are tight, then the cam gear might possibly be off a tooth. If I began to suspect that as a possibility I would set-up a dial indicator on each rocker arm and look at where the "foot" of each cam lobe lands with respect to TDC of the piston. I'd be looking for an offset one way or the other. If things seem to line up, I'd eliminate other possibilities before pulling the timing cover off.

Not in NY. The registration fee is based on the vehicle's weight, so the fee doesn't change with YOM plates. NY charges fees for a 2-year renewal period on standard passenger cars, however, Historical registration (required with YOM plates) renew annually.

I learned something today - never seen (or knew about) such a thing. There's probably a reason for that. I wonder what about the design would cause chatter with addition of the friction modifier? Some of the new GL-5 diff oils claim to have the positraction additive 'built-in'. I don't know whether one of those would be compatible or not. You're probably better off going with the GM oil Joe identified above. Interesting that it is rated GL-4, not -5.

It's probably just a loose or poor connection at the switch(es). As Meteor said, pull the door switches up and inspect the connector sockets and pins. Straighten any bent pins or contacts and clean any corrosion or grime. If everything worked before, then this should get them working again.

https://taymanelectrical.com/

Under $10K certainly seems like a good deal. Even so, probably figure it needs $1 ~ 2K of TLC to really make it reliable...

That makes sense because at that time GM was limiting the A-Body cars to 400 CID maximum (well, 401 for Buick). The following year brought the Q-Jet and ended multiple carbs for BOP. (Of course, Corvette still managed to get the 3x2 427.)

Yes - I've done that too. The key is to go slow and pay attention to the new pattern that appears with the first few file passes. That will identify the high and low spots. Work the low spots from behind with gentle hammer/dolly raps. Tap the high spots on the face with the hammer. Once you get close, you can carefully run the file across the face to even the surface before switching to the wet/dry paper with a sanding block. I have a LR molding from my '67 that I replaced with another that was in better shape. The one I removed has a couple of flat spots, but I haven't yet gotten around to straightening it yet since it's now an 'extra'...

As Larry said, I hope whoever ends up with it respects the originality and performs a 'sympathetic restoration'. If it were mine I would first make it a reliable driver and then deal with cosmetic items by repairing what can be saved and only replacing items that can't take any additional wear without disintegrating. From what I see in the pictures, I'd try to salvage and preserve the existing paint.

Are you talking about the small pin perpendicular to the kingpin that intersects the kingpin bore in the knuckle and holds the kingpin in place? I think it is item "AG" in the figure...

This is the currently available GM additive: https://www.amazon.com/ACDelco-10-4003-Limited-Lubricant-Additive/dp/B000QGMXSU/ref=asc_df_B000QGMXSU?tag=bngsmtphsnus-20&linkCode=df0&hvadid=80127027724173&hvnetw=s&hvqmt=e&hvbmt=be&hvdev=c&hvlocint=&hvlocphy=&hvtargid=pla-4583726553782536&psc=1 I would ask that you read the book again, as what you said above is exactly the opposite of my experience. I had chattering on a 1977 Buick until I changed the differential oil and included the GM limited-slip additive. It usually takes some amount of driving (e.g., 20 ~ 50 miles) for the additive to fully treat the clutches.

Maybe the result of a prior accident (albeit minor)? Possibly a hard pothole hit? Or possibly caused by improper sling towing at some time in the past? I'm just glad that it wasn't the steering box!

It's hard to tell from the photo, but if the wheel opening molding is just flattened a bit it may be able to be straightened. I have done that before myself using a hammer and different tools to bend the stainless back into shape. Once the shape gets close it may require making some wooden dollies to get just the shape you want. Once the dent is removed then bodywork the outside surface with ever finer sandpaper. Final pass with some 1500 wet/dry paper and then polish with a cotton wheel on a bench grinder. Many other '60s cars used anodized aluminum moldings which generally can't be repaired, but the stainless steel used on the Riviera at least allows for the repair option.

Good find! There must have been a shiny spot on the rod where the tie rod end was getting caught. Hopefully after the alignment the steering wheel will be set straight and the tie rod adjusters should show roughly the same number of exposed threads.

Same setup on my 2001 8.1 Suburban. Seems to work well; the pedal feels just like the usual vacuum diaphragm type.

Pretty car - nice colors.

Yeah, I see that now - I thought the picture was looking from the back, but the Q-Jet shows otherwise. Anyway, my point was the difference in complexity that ~15 years of EPA regulations made on vacuum engine controls...

Well, I like it better than trying to hold a prybar with one hand while tightening the compressor bolt with the other...

I have to laugh when the vacuum routing diagram shows two hoses! Compare with one for a 1980s Olds V8: