I've used DigiKey for components for electronic pinballs (transistors, capacitors, resistors, etc.) but it's been awhile.  If there is a "Micro Center" store near you, they have a selection of parts like this as well.  Similar to Frys, which closed around here at least.  Big store but they have a couple of aisles of electronic stuff and handy if you have one in your town and don't want to wait on delivery.  I've heard Hobby Lobby has a small selection, too.  Maybe even sells Radio Shack stuff now?

Even back in the 1990s and 2000s, when Radio Shack was still around, every time I went in there, it was hard to get someone to ring up a purchase because all the clerks were busy selling phone plans.

Pat

Wow, never knew there was a tool for that.  Thought the only tool was for installing the seal, not centering the cover on the shaft.  Great to learn!

Pat

I'm sure a custom cam would give the most power, but if you are wanting to stay more factory, you might look at the slightly hotter C8AX-6250-C cam.  Lots of info online but here's a link:

https://www.428cobrajet.org/id-cam

I have a copy of this cam in my '64 390 from Oregon Cams.  A little lope, not bad, but might be marginal if you have power brakes.  My setup has 13" of vacuum at idle (900 RPM, timing at 14-16 degrees).  I'm running a tri-power but I don't think that would make much difference at idle.

What kind of intake?  You'll want something aluminum at least, if for no other reason than to spare your back once you have the original cast iron one off if it's still there. 

Pat

The strong vacuum in the crankcase is odd but I don't know I'd focus on that first.  If the engine and truck is unknown, I'd start with clean fuel and filters as well as rebuilding/cleaning the carb after sitting for 15 years if that hasn't been done already.  Then pull the plugs to inspect for oil fouling, wet from gas, gap, etc. and while out, do a compression check for a baseline, and hook a vacuum gauge to and see what that tells you.  Sorry if these were the general things you'd already mentioned were done.

You mention the vacuum lines.  Does it still have what I assume is a complicated spaghetti from the stock 1986 setup?  I'd definitely be taking a lot of pictures and notes before touching that.

Pat

Make sure the choke is all the way open and fast idle screw isn't touching the fast idle cam.  I had that happen on mine.  The choke wasn't open 100% but I thought it was open enough the fast idle screw would not be in play but I was wrong.

Next thought is that the advance springs in the distributor are sometimes not pulling the mechanical advance out when you are at idle.  More timing equals faster idle.

Finally, next time it is idling "fast", go under the hood and make sure the secondary plates are all the way closed.  Primaries too for that matter.  See if you can rotate them any more shut, indicating they are hanging slightly in the bores.

Pat

Looks great so far.  I'm waiting on the prop for the front to complete the look.    At the speeds I anticipate you'll be running, you wouldn't even need to power it - air resistance would spin it.

Pat

I'm not familiar with the Packard transmission, but a friend of mine had a VW Beetle that worked similarly.  You had to shift it (I think it was a 4 speed but might have been a 3 speed) but there was no clutch pedal which made me nervous the one time I drove it.  You just accelerated in first gear, then backed off the throttle, shifted to second, then got on the throttle again.  Kind of interesting...

Pat