You can spend a lifetime thinking about that carb. The answer for me and others was FCproducts.com. Your carb is 22 years old !

The weber is a valid option and will get you down to one vac line for dizzy advance.

You should have good vac at the reed valve. If not your issue may be leaking intake gasket. Will the truck run? Have you checked every vac line for cracks? You have to pull each line, sometimes they are just hardened and are leaking without the cracking. I would nip off the ends to get back to a tight fit.

<img src="/forums/images/graemlins/patriot.gif" alt="" />