Gary Hall always insisted that only one throat was necessary even to operate the power brakes.
I don't get the same results.
I'm plumbed into the mounting flanges of the intake manifold which is enough volume of vacuum to operate a vacuum gauge normally, it still isn't enough to operate the brakes. I use a Compcams vacuum pump which yields something like 22 inches. The problem is it's noisy.
When it comes down to it a vacuum advance really isn't necessary and a mechanical advance like on the 427 and 289hp Fords is fine.
I've found that 140f/160a works very well for both economy and performance. You can run that proportion way up to 170f mains and continue to gain power.
I've arrived at the combination by trial and error over 30 years, not on a dyno but if someone wants a quicker answer surely a dyno is the intelligent way to go. Why believe me? I can't possibly be right? I wouldn't be surprised if it made me look like the village idiot but I'll stand by my current conclusions.
I also discovered that I notched the rear decklid too quickly and that it will clear the rear carbs without notching it.
I also discovered that the fuel plume will stay inside the stacks if you use a 5" tall stack.
Inglese had the side drafts on his 66 GT350 when he blew it up in front of the ice cream store. It has a little more room under the hood to clear then a Pantera does but you might want to put some type of rpm limiter on the engine. I don't think it will like 9,000rpm?
You're welcome to call on me anytime but I noticed someone using the term "batshit" lately in description? So I adopted the motto and had some t-shirts made up. Makes people keep their distance so works better then pepper spray.