Downside to vacuum dizzy on street/strip car ?

I'm looking at replacing my Pro Comp mechanical distributor because the bearing is getting noisey with one from Firecore50.

Are there any disadvantages to using a vacuum advance dist on a street/strip car ? I drive my car as much as I feasibly can around town including 15-20 mile runs on the hiway.

67 Dart
440
10.4 comp
Old grind .509
OOTB sidewinders
RPM intake
750 DP Holley
TTI headers
3500 PTC
3.91 gears
275 DRs

Thanks

For a street car vacuum advance is for me. For street I have no down side.

if your driving run the vacuum advance.

Why, certainly there is a downside. The car will get better mileage and you may find yourself in some discomfort waiting for the fuel level to drop far enough that you can stop and take a trip to the restroom. Also you may drive right past the one (in)convenience store with a smokin' hot lady behind the counter.

Other than that I can't see any downside.

R.

The initial setup taking some tuning?

Lol @dogdays - nailed it

tune the systems to get the most out of it & there's alot to be gained. initial/total/springs/can in that order

Thanks for all your replies.

I was just curious as I've seen a lot of vacuum distributors plugged or not present on a lot of cars and wondered at what point there is a reason to eliminate it.

Too many reading "Hot Rod" magazine...

From 1966...

Kevin

Alot of iron headed engines built from the 60's to the 90's (no aluminum out there yet for most mopars) were built with open chamber iron heads and no quench. When these guys added alot of mechanical advance they were getting pinging at part throttle with the vacum advance hooked up as they could be seeing up to almost 60 degrees advance at part throttle about 3000 rpm. Problem was with iron heads and no quench and the cheap gas many people just unhooked the vacum advance to stop the pinging. But today with aluminum heads and quench and with custom cams to keep cyl press low enough for pump most can get away with 50 or more degrees at part throttle even on pump and of course at wide open throttle they only have the mech advance around 32 to 38. I saw that alot. As for me I got a great deal on a race dist with no vacum advance so I cant run one or I would if I had it. But my car runs good since I have alot of very fast mech advance but I could get better part throttle milage with a vacum advance as I would just have to tune it in. Also race cars dont use the vacum advance since they are mainly at full throttle most of the time and many saw that race cars did not use the vacum advance so they thought they would be faster without it. Ron

can we get an amen here? i was in the '60's and we, as kids, were taught that a vacuum advance was a power loss; nonsense! glad i grew up, or sorta grew up.

AMEN

Whole lotta words to say that some can't tune an engine.

I drove my 64 300 with a warm 413 all across the US with vacuum advance. No aluminum heads, at the time I think only Koffel made them and those heads were overkill for anything with plates. So I ran 906 heads on my 413.

Wiht minimal tuning it ran just fine on 93 octane.