do I need a single Vac dizzy for a 5200?



so to put a Holley 5200 on my 68...I need to switch to a single vacuum dizzy (note applied use of learned word) and switch my pertronix I over to it...then I can put in a 5200 with the stovebolt and clifford adaptors?

is there another option and still use a 5200? I wanna keep my dual vaccuum...

Just when I thought I had decided...that adds some bucks to the project...

come on...I know some of you have YOU have a single or dual vacuum?
Howdy Chas:

This is not a desperated decision. Do whatever you want. Many have made either work. If you chose to use the 5200 with your current dual (advance/retard) vacuum distributor, plumb the advance side of the cannister on the distributor to a full vacuum source and tune from there. Depending on which 5200 you use, it may not even have a ported vacuum source. Leave the vacuum retard nipple alone and open. That's the one closest to the distributor body. Do not cap it. If you do the other side, the vacuum advance side, will not work properly.

I have forgotten what year engine you're working with and which distributor.

If you don't have a '68 or later distributor you will not benefit from centrifugal, or mechanical advance. I seem to recall that you were having concerns about mileage in previous posts too? '68 to '72 point type distributors (good, better if upgraded with a Ignitor, or better yet, an Ignitor II) have centrifugal and vacuum advance. The 1st iterations of the Duraspark electronic ignition system (better) started in '73, to be replaced by DuraSpark II (best) sometime in '75. Any of these are better than the '67 and earlier vacuum advance only distributors. In all cases a single vacuum cannister is better, cleaner, easier to tune, but not essential.

What will you do?

Adios, David
While we're on the topic..... with the price of regular gas at $1.85/gallon here, I'm thinking of pulling my motorcraft 2bbl off as it's too much for a stock 170 with the 1.5 intake hole and my mileage has gone way down. I have a couple of early one barrel carbs around, but I'm running a new '68 (single advance ) distributor in my '64 engine (yes, it's a late '64 ;) )

Pony Carbs says the later vac/mech. advance distributor and early carbs are not compatable as the early carbs are desinged to run with the early vac. advance only distributors- but they don't say what will happen if you run with the later distributor. If I run an early carb with the later distributor, will I get too much advance, not enough, or some other problems? Or is the problem only with running an early distributor and later carb? I don't want to put my worn out '64 distributor back in :unsure:

David, I have a 68 with the dual advance. My main concern was improving gas milage...with an added bonus of improved performance. I NEED to get a new carb as mine is leaking (wet on one side) and gas milage has dropped.

I originally wanted to go with the 5200 but someone's post (maybe you) mentioned only single advance works with it. I did not know if you could just plus it up or if I couldn't use at all.

I still think I can make a 5200 work as I am not too heavy on the pedal. I was concerned I would buy something that didn't work and be stuck. Either case...I think I will have someone put it on for it is hard in my condo garage to do work.

Still considering the weber 32/36....the drawback is the square air cleaner..

I am trying to make sense of all this. Thanks for your patience and help.
Howdy back Chaz and Thor:

It's been a while Thor. I would not hesitate to use your '68 distributor with a "Load-A-Matic" Autolite 1100, '64 - '66 carb. Just plug the Spark Control valve and use manifold vacuum to the distributor. You may have to retard your initial setting to the 10 degrees of advance or less at sea level. This combo may actually get you a little better mileage at cruise, because the vacuum advance will be at it's highest at steady, high vacuum conditions.

Ideally, you might do better with a Carter YF for a 170 for mileage (150 cfm), or a 200 (187 cfm) version for a little more power. If you do, hook the vacuum line to the ported source on these carbs. This is what your '68 distributor is designed for. The YFs are supposed to be an improvement over the Autolite 1100s, but are a more complex carb. In theory, they have a better idle and choke circuitry, and transitions. It's weakness is the accelerator pump system, so when you start to get hesitation on acceleration you'll know that it's time for a rebuild kit.

The only down side is that YFs were converted to cable linkage and you'd have to adapt your air cleaner to look stock.

Chaz- You might start by rebuilding your leaky one barrel, just for the adventure and the education. I can be done in a condo garage, or the kitchen table, if you DF (Dominant Female) will allow. I use a cookie sheet pan and lots of rags to disassemble. Then take it out side to clean with carb cleaner and soak. Once cleaning and dissolve is done, take it to a tire shop and use their air hose to thoroughly blow out all orifaces and dry. Clean is paramont!. Then I let it set in the sun for an hour or two to get rid of the odors. Then begin reassembly. Study the instruction sheet in the rebuild kit thoroughly. Go slow and double check every step. This is an excercize in patience.

You'll be amazed at what a fresh rebuild can do for an old, one barrel carb. and it's a good foundation for getting a H/W to work right.

Adios, David
luckily when I bought my inline 6...the previous owner kindly included an old holley (dont know model) and it looks like an old motorcraft (dont know this one either)

That way I can rebuild and have little down time.

I am going to take my extra carbs to a carb shop and see exactly what they are and maybe get a rebuild kit. I heard there is like 100 parts or so...oyé!

DF...I got one of those. Didn't come with the car, came with the ring.