You might have to get the motor and carb back to stock and start from there if you have not already done that. Put the stock main jet in, double check the pesky power piston is free and moving, and double check the float level. Accelerator pumps are problematic. This new fuel plays havoc with them. See if yours is messed up and replace if needed. From there, I would check to see that the vacuum advance is working. By that I mean it is moving with the change in throttle blade position, and that the rubber diaphragm inside the advance can is not leaking or ruptured. I have a little piece of stub flared line and a rubber hose to test mine. Apply a little vacuum, or just suck on the hose, you will know instantly of the diaphragm is good or not. If the advance is good, make sure no vacuum leaks at the steel line from the base of the carb to the vacuum advance. Adjust the idle mixture and idle speed screws.
From there, double check you have the timing set at tdc, just for starters, so the powerglide adapter plate pointer is pointing at TDC. When I get home from work tonight, I will post a photo of a Sun Tune up card for the 58 Pass. 235. This will help you with that if you don't have any materials to reference.
If the timing is set properly, then you might consider taking the top part of the distributor apart, and remove the distributor plate, and take a peek at the mechanical advance. It needs to be clean, both springs need to be intact and the advance weights should be free and moving. If not, you will need to clean out the junk (there are two drain holes on the bottom of the distributor housing so you can use a little carb spray and a small soft brush to clean it up a bit.) As HRL noted, use the correct base gasket on the carb.
Last edited by Dragsix; 02/05/2020 5:10 PM.
