[68 P.O.S.]

Straighten out your timing first or nothing else will be right. Sounds like you mostly have it handled at ~36 degrees total timing. Those Moroso HEI kits aren't really meant for a daily driver. Personally, I would put the stock weights and centerplate back in and put in springs that allow full advance between 2500-3000 rpm. Adjust your vac advance to provide 10 degrees of advance and then connect it to manifold vacuum (which helps with running cooler). Also, spark plug gap with HEI is 0.045.

Next I would move on to the carb. You rebuilt it so that's a good start. Edelbrock carbs can be finicky if not set up right. Set everything up to Edelbrock specs. Double check the float drop and rise. Fuel pressure must be restricted to no more than 6 psi (with a fuel regulator or a <6 psi fuel pump (Edelbrock recommends 5.5 psi)). Your accelerator pump should be in the middle position. These carbs need a spacer, or else they percolate fuel, so your spacer should work fine. Once carb is setup, you need to set the transfer slots in the main throttle bores to look like a square using the throttle adjustment screw. Once square, don't touch the throttle adjustment screw again. Then you can throw the carb on and give it a whirl. With the carb adjusted as above, the transfer slots squared,, and the vac advance connected to manifild vac, your idle should come out to 750 rpm. You'll also need a calibration kit to change jets, rods, and step-up springs. But you can do that after you get it running.

For your cooling, I would look at every part of the cooling system to make sure it's functioning correctly. Do a back flush of the radiator (heater core too) to get any possible clogs out. Correct the heater hose routing. Make sure your water pump and thermostat are functioning correctly.