Couple of things I learned the hard way:
Buy a new carb. Don't bother with rebuilding an old one. You'll end up at the same price point in the end.
HEI: I went with an ebay EFI distributor. It lasted 2 years before going bad but it was cheap so I just bought the same one again. Also be sure to remove the resistance wire from the firewall to the distributor.
Do it in stages. I started with Langdon headers and made my own heat plate. Just get the Langdon heat plate. You won't save money making it yourself. Sealing it is a PITA. I used a ton of RTV.
As far as staging goes here's the order I'd do it in if I did it again:
1) HEI and electric fan. Runs so much smoother that way and frees up a couple ponies. I used a pusher style fan and bought a 3 core radiator on Ebay. came out nice.
2) Offy intake and carb. Use the exhaust heat for now.
3) Langdon split header and exhaust. Heat the carb with water. A couple ways to do it. I tapped into the heater hoses at the fire wall. Others tap into the front of the engine. If you have a tapped hole on your thermostat neck that'll make life easier.
4) Cam. On my Camaro I was able to change the cam by pulling off my grill, unbolting the engine mounts, and jacking up the engine. This gave me just enough room to pull it out the front. You'll also need an aluminum cam gear when you do it and new valve springs. Lifters as well.
5) Head. This is where that spare engine might come into play. Get lump ports and oversized valves.
6) Transmission. I had a powerglide. Swapped to a 2004r. HUGE difference. I highly recommend this one. You can get them used pretty cheaply, wire in the lockout, new linkage, and gear selector bezel. Worth every penny!
7) Gearing. Once you have all that done you can now get better gears.
You can see the heater lines at the firewall. I used brass T's as I couldn't get the plastic ones to hold up.
The linkage for the throttle on the 2004r. Bought a kit somewhere for it. Been a while so I can't recall where. It's critical this is done correctly or you'll burn up the trans. I did it with the trans pan off and a caliper. The other option is with a pressure gauge.
Stovebolt Headers (Langdon). You can have him ceramic coat or buy a can of it at your parts store and do it yourself.
Original cam gear. See that hole with the screw behind it? That's the retainer. I got extremely lucky with mine. When I pulled the cover the engine happened to have been stopped at the perfect spot.
New cam gear. Nice and shiny. Original is a composite and you'll never get it off without breaking it. New one is press-fitted on.
....and for the most important advice I can give you!
USE THE RIGHT OIL! Modern oils do NOT have the right chemical make up for solid lifter engines. Brad Penn makes a good oil for your car. There are others out there as well.
I did my research and on paper Mobil1 appears to have the right stuff. It does NOT. Wiped a cam.
Find a local machine shop or speed shop. They'll sell you the right oil. Don't go to NAPA or other big chain parts stores. In a pinch you can use Valvoline VR1 but I prefer the good stuff.
I live in Hanover, PA now. Somewhat local to you. If you get stuck sometime reach out to me. I love working on these old engines and have enough experience to not do things like I did again...
