So, checking out the engine...
It's full of oil, and the oil looks brand new. Further confirming my suspicion that this engine hasn't been used at all since it was rebuilt in 2013.
It won't start on it's own, but will start if you spray fuel down the carb. Even then, it backfires and sputters and is hard to start. I believe there are fuel issues and the spark timing is off. It may have intake manifold leaks, too.
Since this thing is old and has been sitting for a decade, I'm just going to run through all the basics and make sure they're right...
The inside of the fuel tank looks okay. Just a little minor surface rust. I'm not going to touch it. It badly needs a new fuel cap, though.
The steel part of the fuel line looks good. I replaced the rubber hose sections just for insurance purposes. I also installed a new inline filter.
The mechanical fuel pump looks pretty old. These pumps are fairly reliable though, and the cool thing about a mechanical pump is that it naturally wants to pump more fuel when the engine turns faster. I went ahead and replaced the diaphragm inside, and opted not to install an electric pump.
The carburetor has been upgraded, but the upgrade is definitely a questionable one. The carburetor is definitely a better model- it's a Weber 38 DGAS dual-barrel downdraft carb that's obviously better than the original single-barrel carb. This carb looks like it's already been used for three decades though. and the throttle linkage points the wrong direction. Somebody tried to make some crappy linkage adapter, but the screws are weak and it doesn't work at all. This model also has a water choke, but there are no coolant lines attached to it so it's not doing much.
I decided to get rid of the carb and bought a brand-new Weber of the same model to replace it. I got the DGES version with an electric choke, so I wouldn't have to mess with running coolant lines to it.
I decided to ditch the original throttle linkage completely, and replaced it with a cable. I got this Lokar TC-1000-HT60 universal throttle cable kit from Summit. I also got a throttle cable adapter for the carburetor, and a bracket that I had to customize a little bit.
I also had to add a new throttle return spring. Don't want that throttle getting stuck open on me!
I made my own bracket and adapter to connect the other end to my existing pedal. I designed the bracket so that it would bolt to the existing bolts that hold the accelerator pedal to the floor:
The cable makes the accelerator pedal feel a lot smoother and snappier, and it operates the throttle valve perfectly. Much better response than the heavy old steel linkage.
The intake manifold has been swapped out for a performance Clifford "6=8" intake. Reading up on slant sixes, this is supposed to be a pretty good update. The owner tossed in the old stock cast iron intake, which looks considerably smaller and shorter, with narrower runners.
That's cool, the intake manifold's a keeper.
So, after all that, the engine will now start. It requires a lot of help in the form of cranking endlessly and futzing with the throttle. It still backfires and grumbles and you have to keep the throttle open too far, but at least you can now keep it running without spraying fuel into it.