Was thinking of adding a vacuum advance canister

Im thinking of adding a vacuum advance canister to my MSD 8548 Pro Billet distributor IF its even possible.
Is it worth it during highway driving or am I just setting myself up for issues?
I've been running this distributor for years and haven't had any issues NOT using vacuum advance.

 

I agree with Larry. I contacted MSD and they said it wouldn't work. I found a brand new Mallory on ebay and bought it instead.

 

If your driving it on the street no less highway miles I would go as far as spending the money to get a Dizzy in the motor that has vacuum advance, maybe you could even borrow one!?

You don't realize how much unburned fuel is wearing out your cylinder walls and getting into your oil during part throttle and cruse times!

Even if your only able to add in just 8 degrees of advance it's worth it cost wise!
If you need real world proof then find a nice long flat stretch of road that you can do 55 mph on and bring your timing light along.
Drive that stretch of road and the stop and add in 6 to 8 degrees more base timing and make the drive again and see what you think!

 

Mark, Question/answer from Summit:

I have previously purchased a 8548 distributor which works fine; however, I could really do with a vacuum advance. Does MSD make a distributor to fit the Buick 215 that has a vacuum advance?

Thanks in advance
Allan

Asked by ALLAN on May 12, 2018

A:
Thank you for your question. MSD does not offer a vacuum advance version of the 8548 Pro-Billet distributor. However, we do offer a similar distributor from Pertronix under part number PNX-D351710.

Summit Racing Answer - August 02, 2018

....And you don't want to buy a Pertronix!

 

I would say probably not! Good call Larry.

 

Thanks for the info guys
I was thinking about it some more,and I think Im going to leave well enough alone, I've had zero issues with my MSD set up since install way back when.

 

That's actually a good idea. The 8548 non-vacuum 350 dist. needs an MSD box. The 8552 doesn't, and it has the vacuum advance PLUS a built in Rev limiter!

 

Or if they say no, ask to buy one if the 455 distributors without a gear and buy the 350 gear from them at same time.


Probably would get done faster if you asked someone like Summit to ask them for you, have them enlighten them?

 

Nope, just the opposite. Summit didn't have a listing for a 350 dist gear when I ordered mine. Had to deal directly with MSD, and they would not pull one off a stock dist to sell either, I tried. Hopefully they now have a part # for replacement 350 gears.

Vacuum advance may be beneficial with my cam as my high maintaince girlfriend says my car stinks and is gassing her out!
Might help at idle with 35* overlap.

 

Is this like the other MSD distributors which have a .500 shaft, so a "stock" gear has to be honed-out to fit? OEM diameter is .491 or something close.

Does MSD actually sell a 350 gear suitable for their distributors?

 

Yep, MSD with vacuum advance for the 350, that would be the ticket. As soon as I get closer into 'distributor mode', I might check to see what's possible.

 

Didn't you just buy a new dist. gear? If so you can get the 455 distributor and swap the gear.

 

Yup, if I find a 455 vac dist. for a good price, I'll have the setup. Or I can lockout timing and go with start retard. Won't help at cruise around town advance though, but will keep high maintenance happy at idle.
Will manifold vac function a dist properly with only 5" ?

 

You should have more vacuum at cruising speeds than what you have at idle, especially when you're in O/D I would think, WOT though would go to zero.

 

Not as concerned at cruise speeds, more so at idle. Will 5" actuate the vacuum can diaphragm fully at idle??