Thanks for the advice, still need more
 

Thanks to everyone that replied to my previous posts. It made the intake manifold/carb and head install much easier. I'm ready to move on with more mods and am looking for more advice.


1. The Mallory dual point I have, ZC275AX, has a provision for vacuum advance. Should I use this feature or block it off and go centrifugal only?


2. Has anyone used the Mac's spin on filter conversion? Any problems?


3. The car ('49 sedan) currently has dual exhaust using the stock exhaust manifolds. Would like to upgrade with something that would not require any fitting or grinding.

Re: Thanks for the advice, still need more
 

1, By all means. Hook it to manifold vacuum.
2, Not used one.
3, Again, no experience on that model.

Re: Thanks for the advice, still need more
 

Use the stock filter as it does a better job of filtering.

Re: Thanks for the advice, still need more
 

Manifold or venturi? The manifold vacuum on the engine is 20.5"hg at idle. I think that would pull it to full advance. The Holley 390 that I'm using has a port for metered venturi vacuum that is zero at idle and increases to 10" at 1500 rpm.

Re: Thanks for the advice, still need more
 

Dunno. I'd use manifold, but maybe someone else can say if venturi would be better.

Re: Thanks for the advice, still need more
 

Thoose mallory distributors had something called a spark control valve mixed into it just to complicate things if i remember right...
Taking vacuum from intake and having venturi controlling the valve...

Re: Thanks for the advice, still need more
 

All of the Mallory distributors with vacuum I have seen have a "vacuum brake" like the pre-'49 Ford distributors. (Actually, it should be called a "vacuum unbrake, but that's kind of awkward). As such, I believe that it should be hooked up to manifold vacuum rather than venturi vacuum. I would try it both ways. I had a vacuum over mechanical converted SBC distributor on my '51 and couldn't get it to work right. I changed in a mechanical only Mallory flattop and am much happier with the way the car runs.

Re: Thanks for the advice, still need more
 

This is the little gadget i thought of..
https://www.ebay.com/itm/Vintage-Mal...4AAOSwteRdseDd
Think this was an option either to correct or improve the spark advance...