63 Distributor

[Richard S.]

I am looking for information on compatibility of a 69 vett distributor with mechanical advance and tach drive for use in my 63 vett 327 cu in 340 HP. I have weights and mechanical advance to put in the 69 distributor so as to make it look like a 63 340 HP unit. But is the drive gear and tach drive gearing the same?

[Duke W.]

Re: 63 Distributor

A '69 tach drive dist. is basically the same as '63 except for the spark advance map. If it still has the ID tag determine what '69 engine it is from in the NCRS Spec Guide, then tell us what the centrifugal and vacuum advance specs are from the AMA Specs or CSM.

For sure you will need a B28 VAC, but I need the centrifugal data to recommend a decent set-up for a '63 340HP engine assuming it is OE spec. If not, what modifications have been made, especially the camshaft.

Duke

[Joe L.]

Re: 63 Distributor

I am looking for information on compatibility of a 69 vett distributor with mechanical advance and tach drive for use in my 63 vett 327 cu in 340 HP. I have weights and mechanical advance to put in the 69 distributor so as to make it look like a 63 340 HP unit. But is the drive gear and tach drive gearing the same?

Richard------

The 1963 and 1969 distributor drive gears and the tach drive gears are functionally identical and 100% compatible and interchangeable.

[Stuart F.]

Re: 63 Distributor

But the football man, how about the football? You change weights till the cows come home, but don't they need to work off the shaft cam? I've looked at my 63 340hp cam (football) end side by side with a 71 unit I have and the difference is obvious. I even rejected a new replacement 63 SHP shaft for the same reason. I miced it, and even traced the profile of each cam. They were noticeably different.

Stu Fox

[Duke W.]

Re: 63 Distributor

I can take any single point distributor and with a VAC and a set of springs come up with a spark advance map that's reasonably in the ball park for any OE engine configuration or a modified engine. Just follow the general guidelines in the San Diego Tuning seminar. The link has been posted many times.

Duke

[Joe R.]

Re: 63 Distributor

Richard,

Take the 69 distributor to a person who has a Sun Distributor Machine and he will set the curve to the specs you give him on the cam, heads, carb., etc.
Most people who possess a Sun Machine are knowledgeable about setting up distributors.
Ask around in your area for such a mechanic.

JR

[John D.]

Re: 63 Distributor

Richard, You said you have a 63 with 340 HP. If you have the stock cam then turning a '69 distributor into a '63 is a piece of cake.
Don't know if there is any cosmetic difference.
Here's some info what a '340 or a '360 Fi distributor has. Starting from the top. The football is stamped 54. (not 54W), The cam is stamped 724 on the bottom side. The weights are #37. Original vacuum advance is 201 15 0r 16 (forget). Replacement is what Duke said. B28.
Don't mess with DR points and condenser.
In fact i highly suggest you have Don Baker handle this job for you as he has all the parts including the football. If your shaft, bushings and tach gear are in good shape then the whole job won't be terribly expensive. Call him at 815-498-9522 as he's not into email that much.
Distributor cap is available for $20 or so from NAPA. Black, lower tower, coppe.r RR168. Don will supply the rotor as the auto store ones today aren't that great. John

[Stuart F.]

Re: 63 Distributor

Does the 69 have a thrust button for the tach drive cross shaft? If not, probably should be modified, or if it does it probably should be replaced. If at all possible, you want to save the original main shaft and cross shaft as a matched gear set. The new repros are not that great, i.e. The welding of the football, the machining of the gears, etc. Just a thought from what I went through with my 63 340 hp unit.

Stu Fox

[Joe L.]

Re: 63 Distributor

Does the 69 have a thrust button for the tach drive cross shaft? If not, probably should be modified, or if it does it probably should be replaced. If at all possible, you want to save the original main shaft and cross shaft as a matched gear set. The new repros are not that great, i.e. The welding of the football, the machining of the gears, etc. Just a thought from what I went through with my 63 340 hp unit.

Stu Fox

Stu------


Original 1969 distributors did not have the nylon thrust button. However, later manufactured SERVICE distributors of the original 1969 part numbers did have the button. So, it depends upon when the distributor was manufactured.

[John D.]

Re: 63 Distributor

Joe's right for sure. One is better off fixing up his old original distributor than using a NOS service replacement one. Why you ask? Because Delco used parts that they left over. Those NOS distributors could be running most any cam. Most any football too and various other parts.
I didn't learn this on my own and have to give this credit to Don Baker. He taught me. John D

[Mel H.]

Re: 63 Distributor

Richard, You said you have a 63 with 340 HP. If you have the stock cam then turning a '69 distributor into a '63 is a piece of cake.
Don't know if there is any cosmetic difference.
Here's some info what a '340 or a '360 Fi distributor has. Starting from the top. The football is stamped 54. (not 54W), The cam is stamped 724 on the bottom side. The weights are #37. Original vacuum advance is 201 15 0r 16 (forget). Replacement is what Duke said. B28.
Don't mess with DR points and condenser.
In fact i highly suggest you have Don Baker handle this job for you as he has all the parts including the football. If your shaft, bushings and tach gear are in good shape then the whole job won't be terribly expensive. Call him at 815-498-9522 as he's not into email that much.
Distributor cap is available for $20 or so from NAPA. Black, lower tower, coppe.r RR168. Don will supply the rotor as the auto store ones today aren't that great. John

John...thx to all for the info/posts on this topic. Been reading the archives looking for correct football & cam numbers for my '63 327-340 so this was timely and helpful. Its kind of a pet interest of mine.

A few yrs back at one of the shows I asked Don Baker about the correct nbrs for my '63 340hp. He pulled out a hand written reference sheet and said the cam should be #724 as you noted, and the football should be#94 for the SHP engines. I made a mental note of these numbers from our discussion that day and have been trying to confirm them ever since.

So far I've only found references to #54 for the '65 327s in the archives, but nothing directly on the '63 340s. But, it sounds like there is consensus on #724 for the cam..... is there a definitive answer on #54 vs #94 for the football? Also....whats the diff in 54 vs 54W?

Anyway, I currently have a #54 football on a #522 cam, giving 22* of cent advance, all in at ~2700 rpms. It provides a pretty nice advance map, but I remain on the prowl for a #724 to make more authentic.

Again, appreciate the info.

Mel

[Duke W.]

Re: 63 Distributor

What you have is pretty close to ideal. My starting point centrifugal recommendation for the 327/340 is 24 @ 2350 - same as OE '64-'65 SHP/FI.

Set total WOT advance at 38 at over the speed that centrifugal is all in, which you say is 2700. Also make sure you have a B28 VAC that is connected to a full time vacuum source. Then do some road testing including loading up the engine at low revs to check for detonation. If it doesn't detonate, I suggest you leave it alone and go on to another project. If it does detonate, back off a couple of degrees, but no more than four.

It's common on these old cars that distributors may come from a different engine or be made of of a hodgepodge of parts. (See the nearby thread on the '71 L-71). The best setup is to get the centrifugal in as soon soon as possible, without detonation, with a VAC that passes the Two-Inch Rule, connected to a full time manifold vacuum source, with total WOT advance nominally 38 with a range of 36-40. If you can achieve this, you are in the ballpark, and there is no real need to chase down OE parts that can be rare and expensive, and can't be seen during Flight Judging.

The basic rule of thumb as stated in my 2012 National Convention presentation is that if you are within three degrees of the optimum advance for every operating condition, the engine will make 99-100 percent of potential power and lowest fuel consumption for that condition, and the absolute best we can do with these crude, but simple mechanical analog controls is to get it in the ballpark.

You should to a "blueprint overhaul" as discussed here many times (see a Dec. 2012 thread started by me on the subject). It's easy to do and the disassembly/assembly procedure is in the 1963 Corvette Shop Manual.

[John D.]

Re: 63 Distributor

Mel, I have owned a NOS FI main shaft with a 54W on it for many years. Don Baker won't use it on our restorations for the following reason.

The service replacement 54W was designed to be used with the 500 series distributor cams.
The stock 54 football/mainshaft was for the 700 series cams

You can use a 54W mainshaft if you use the 500 series cams. But if you mix the parts up then you won't be able to get the distributor set up to stock specs.
THe above inflo came from Don Baker. Now I know why my 54W NOS mainshaft is going to rust away here. (not sure if I still have it)
Trick if you have a NOSo 54W is swap out the football.

Sorry Mel but I don't know anything about the low HP distributor cams (carb that is)

Now friends before Don Baker came around and you wanted a new main shaft for your 58 to 65 FI distributor (many shafts) all you could get was a generic part with one football that fit all. JD

[Timothy B.]

Re: 63 Distributor

Can say what the difference between a 54W and a 54 main shaft cam is but I can tell you for sure the #54 is the OEM production part. Also, don't know the difference in a 724 weight base cam vs the 524 but again the 724 is the production part and it's the same on carbureted cars as FI for 63. Funny thing is what what I have seen the 7 numbers phased out when the 5 numbers started but that's just my observation and the centrifugal advance seems to match these last numbers, (724-524)

[Joe L.]

Re: 63 Distributor

John...thx to all for the info/posts on this topic. Been reading the archives looking for correct football & cam numbers for my '63 327-340 so this was timely and helpful. Its kind of a pet interest of mine.

A few yrs back at one of the shows I asked Don Baker about the correct nbrs for my '63 340hp. He pulled out a hand written reference sheet and said the cam should be #724 as you noted, and the football should be#94 for the SHP engines. I made a mental note of these numbers from our discussion that day and have been trying to confirm them ever since.

So far I've only found references to #54 for the '65 327s in the archives, but nothing directly on the '63 340s. But, it sounds like there is consensus on #724 for the cam..... is there a definitive answer on #54 vs #94 for the football? Also....whats the diff in 54 vs 54W?

Anyway, I currently have a #54 football on a #522 cam, giving 22* of cent advance, all in at ~2700 rpms. It provides a pretty nice advance map, but I remain on the prowl for a #724 to make more authentic.

Again, appreciate the info.

Mel

Mel-------



The use of all the correct and particular internal distributor parts (i.e. mainshaft w/"football, cam, weights, springs) is what Delco-Remy used to create specific distributor advance curves and specific distributor part numbers. If you want to create a specific distributor part number, you can do it the same way. However, it's not the only way a distributor of the original advance characteristics can be created. Someone with a Sun Distributor Machine and the knowledge to use it can re-create the exact original advance characteristics even without the correct original internal parts. No one will ever know the difference.