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[C2] Distributor length

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Old Mar 29, 2022 | 09:35 PM
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Default Distributor length

Basically the REAL question here is about the distributor length and what it will fit in but I am going to give you the background on all of this.

Ok, so a while back I bought a K66 UHV ignition system basically for the coil and intending to convert a tach drive points distributor with the parts out of non tach drive distributor that came with the system I bought. Turns out converting the distributor with the parts from the other distributor is not possible. So I am going to sell the complete system that I bought but am now trying to figure out what I actually have. I have been all over Chevelle, GTO, Z28 and Chevy Super Car sites trying to figure it out in addition to a site with a lot of info about UHV systems.

The distributor I have with this system rotates the same direct as Chevy but is 1/4” shorter than a Chevy distributor measuring from where it sits on the engine block to the bottom of the shaft. which is 7 3/4” verses the known Chevy distributor that measures 8”. Will this shorter distributor seat probably and work in a Chevy BB engine?

Regarding the system I am trying to identify it MAY be a put together system based on what it includes:

1. The distributor has absolutely no part numbers on it.
2. It has a vacuum advance unit on it that is a somewhat rare Z28 unit which is marked MS 400 15 not sure if this UHV system was available as a factory installed option or just an over the counter parts on a Z28?
3. The coil is a #248 CD which is supposed to be for both Pontiac and Olds but will also work with any vehicle with UHV system.
4. The UHV amp box has a very lightly stamped part number that LOOKS to me like 1116030 but I have not been able to find the application.

Here is a picture of the system.






Last edited by 68hemi; Mar 29, 2022 at 09:41 PM.
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Old Mar 30, 2022 | 05:03 AM
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Didn’t like our answers on Team Chevelle. I stand by what I wrote over there
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Old Mar 30, 2022 | 09:13 AM
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Originally Posted by Nowhere Man
Didn’t like our answers on Team Chevelle. I stand by what I wrote over there
I don’t care what your opinion was there since it has yet to be determined what the original application was that you seem to GUESS at. and it is yet to be determined what I really have or what the original application was at this point. Your opinion on it’s value was ridiculous. Have you ever tried to buy even a good K66 coil for an example lately?

My question here is the same as I have asked on other forums regarding the distributor length and if it will work in a BB Chevy engine that so far NO ONE has answered.
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Old Mar 30, 2022 | 09:18 AM
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Originally Posted by Nowhere Man
Didn’t like our answers on Team Chevelle. I stand by what I wrote over there
This is somewhat off topic, but I had asked a question over at Team Chevelle about a year ago, and got roasted; called everything from a liar to a know nothing poser. The question was a simple one. I just asked if anyone else had owned or known of open chamber iron heads on a 1970 Chevelle SS396-375. I was informed, not very politely that it never happened. But it did. I helped work on a friend’s 70, and when we had the heads off checking for damage to the pistons because the green heat treated Chevy valve keepers failed. They were open chamber iron. You may know that in 1970, the 375 hp engine option was a very short production run- about 2 months. It was replaced with the SS 454 LS6. They may be really good guys over there,but I lived it and worked on it as new, and I didnt appreciate the venom that spewed from some of them who think they know it all. End of rant. OP- didn’t intend to hijack your thread, just got carried away in the heat of the moment .

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Old Mar 30, 2022 | 09:21 AM
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Originally Posted by 68hemi
I don’t care what your opinion was there since it has yet to be determined what the original application was that you seem to GUESS at. and it is yet to be determined what I really have or what the original application was at this point. Your opinion on it’s value was ridiculous. Have you ever tried to buy even a good K66 coil for an example lately?

My question here is the same as I have asked on other forums regarding the distributor length and if it will work in a BB Chevy engine that so far NO ONE has answered.
This is just guessing, but could the distributor possibly be off of a BBC truck application? It is a curious item for sure.
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Old Mar 30, 2022 | 09:29 AM
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Chevrolet distributors Bb and SBC are 7 3/4" from the bottom of the mounting base to the bottom of the gear. The bb truck block uses a different length.
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Old Mar 30, 2022 | 09:35 AM
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Originally Posted by vettsplit 63
This is just guessing, but could the distributor possibly be off of a BBC truck application? It is a curious item for sure.
That is a possibility as they apparently used these UHV systems on HD trucks, military vehicles, on Oldsmobiles, Pontiacs, Chevelles, Camaros and we’re sold over the counter as well as factory installed on SOME of these cars. I just don’t know if 1/4” difference would keep this distributor from fully engaging ad working properly? I would like to sell the complete system but need to know what it will fit and work properly in. I don’t want someone to just take a chance on it like I did that did not turn out well for me.

I believe some of the old truck engines were what they call high deck blocks.I would think they would need a LONGER distributor if I am understanding what that is correctly?
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Old Mar 30, 2022 | 09:38 AM
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Originally Posted by 68hemi
I don’t care what your opinion was there since it has yet to be determined what the original application was that you seem to GUESS at. and it is yet to be determined what I really have or what the original application was at this point. Your opinion on it’s value was ridiculous. Have you ever tried to buy even a good K66 coil for an example lately?

My question here is the same as I have asked on other forums regarding the distributor length and if it will work in a BB Chevy engine that so far NO ONE has answered.

there is no guessing. These items are not assembly line parts ever used on production cars. Over the counter speed parts don’t bring as much money as assembly line parts. I know what assembly line TI coils sell for.
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Old Mar 30, 2022 | 09:51 AM
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Originally Posted by Robert61
Chevrolet distributors Bb and SBC are 7 3/4" from the bottom of the mounting base to the bottom of the gear. The bb truck block uses a different length.
Well, that means the one I have been asking about is correct for what you listed above. So that makes me wonder what the distributor I compared it to is actually for? The strange thing is that we used THAT distributor in my 66 BB temporarily without a problem?

So, based on what I stated I have in the OP with the Z28 specific vacuum advance unit I should think that this system was likely used on one of those cars. I have not yet had an answer as to weather or not they were factory installed on those cars or if maybe this one was sold to someone that bought one over the counter for one of those cars.
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Old Mar 30, 2022 | 10:01 AM
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Originally Posted by 68hemi
That is a possibility as they apparently used these UHV systems on HD trucks, military vehicles, on Oldsmobiles, Pontiacs, Chevelles, Camaros and we’re sold over the counter as well as factory installed on SOME of these cars. I just don’t know if 1/4” difference would keep this distributor from fully engaging ad working properly? I would like to sell the complete system but need to know what it will fit and work properly in. I don’t want someone to just take a chance on it like I did that did not turn out well for me.

I believe some of the old truck engines were what they call high deck blocks.I would think they would need a LONGER distributor if I am understanding what that is correctly?
Yes the tall deck engines require a longer distributor. I know the China rail spacers sold to allow the use of a standard deck intake on a tall deck motor are 3/8" thick.
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Old Mar 30, 2022 | 10:04 AM
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Originally Posted by Nowhere Man
there is no guessing. These items are not assembly line parts ever used on production cars. Over the counter speed parts don’t bring as much money as assembly line parts. I know what assembly line TI coils sell for.
BTW, I think you mean sold as a factory installed system. They obviously were sold and used on production cars. You need to get your terminology straight. When did I ever say THIS system WAS factory installed? I am just trying to figure out what it may have been installed on factory or not.

Why don’t you just try and find ANY TI coil and see what you can buy it for or the amp box or a distributor if you think they are all over the place for sale? I have been around a old classic cars probably longer than you are old. I was going to Bloomington in the 70s when it was originally in BLOOMINGTON and lots of other swap meets over the years and I have never seen one of these systems for sale ANYWHERE until I bought this one so obviously they were not growing on trees.
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Old Mar 30, 2022 | 10:04 AM
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It's possible that to he gear itself is longer for some reason which wouldn't affect the fit or function. Measure from the bottom of the mounting base to the bottom of the actual geared part of the distributor gear, mine measures just over 6 3/4". If they made the gear itself a little longer on the round part that would just help stabilize the oil pump shaft a little better.
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Old Mar 30, 2022 | 10:30 AM
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it looks like you have a mix of parts to me.

Distributor looks like standard chevy. I think 7 3/4" is the correct length.

the UHV on the box and the red coil are what was used on Oldsmobile. think that was an option around the 1967 time frame on the W30 cars. i think these systems were also used on on the baldwin motion cars. so im guessing someone got their hands on an oldsmobile system, but needed it for a chevy so found a dizzy
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Old Mar 30, 2022 | 10:34 AM
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Originally Posted by Tiger Joe
it looks like you have a mix of parts to me.

Distributor looks like standard chevy. I think 7 3/4" is the correct length.

the UHV on the box and the red coil are what was used on Oldsmobile. think that was an option around the 1967 time frame on the W30 cars. i think these systems were also used on on the baldwin motion cars. so im guessing someone got their hands on an oldsmobile system, but needed it for a chevy so found a dizzy
Very possible but it is not JUST a standard Chevy distributor it is a magnetic pulse TI distributor in order to Mack the system work.

Last edited by 68hemi; Mar 30, 2022 at 12:04 PM.
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Old Mar 30, 2022 | 10:38 AM
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Originally Posted by Robert61
It's possible that to he gear itself is longer for some reason which wouldn't affect the fit or function. Measure from the bottom of the mounting base to the bottom of the actual geared part of the distributor gear, mine measures just over 6 3/4". If they made the gear itself a little longer on the round part that would just help stabilize the oil pump shaft a little better.
As I stated in my OP I measured BOTH distributors from the flange that sits on the engine block when the distributor is installed to the bottom of the shaft.
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Old Mar 30, 2022 | 11:15 AM
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Originally Posted by 68hemi
Very possible but it is not JUST a standard Chevy distributor it is a magnetic plus TI distributor in order to Mack the system work.
yes I get that, i was referring to the length being the standard chevy length.

also im just curious- why cant the tach drive dizzy be converted? im new to TI myself piecing a system together for my car, but from everything i read there is no difference in the housing between TI and points. just wondering what is up with that dizzy

edit to add- i happen to have an original vette tach drive TI sitting here. i measured it is exactly 7 3/4"

Last edited by Tiger Joe; Mar 30, 2022 at 11:23 AM.
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Old Mar 30, 2022 | 12:02 PM
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Originally Posted by Tiger Joe
yes I get that, i was referring to the length being the standard chevy length.

also im just curious- why cant the tach drive dizzy be converted? im new to TI myself piecing a system together for my car, but from everything i read there is no difference in the housing between TI and points. just wondering what is up with that dizzy

edit to add- i happen to have an original vette tach drive TI sitting here. i measured it is exactly 7 3/4"
There is something different in the body casting. My mechanic even took it to a machine shop to see it they could modify it to work but they said no. Otherwise I would have used it. I too have been piecing together parts for a TI system for my 1966 L72 car. I put a new wiring harness in the car and bought the TI harness as well. I just recently bought an NOS TI coil, a TI amp box, pole piece and another part but still need a distributor. I don’t have to tell you these parts are EXPENSIVE. It seems like a lot of these L72 cars are missing this system. Years ago I had a loaded 1966 390 h.p. coupe that had TI and I remember I had to buy some kind of part for the distributor which was still available but this was back in 1987.

Good luck in your search as well.
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Old Mar 30, 2022 | 12:04 PM
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You can take a standard tach drive dist and make it into a TI. They use the same cast iron body.
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Old Mar 30, 2022 | 12:12 PM
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Originally Posted by 68hemi
There is something different in the body casting. My mechanic even took it to a machine shop to see it they could modify it to work but they said no. Otherwise I would have used it. I too have been piecing together parts for a TI system for my 1966 L72 car. I put a new wiring harness in the car and bought the TI harness as well. I just recently bought an NOS TI coil, a TI amp box, pole piece and another part but still need a distributor. I don’t have to tell you these parts are EXPENSIVE. It seems like a lot of these L72 cars are missing this system. Years ago I had a loaded 1966 390 h.p. coupe that had TI and I remember I had to buy some kind of part for the distributor which was still available but this was back in 1987.

Good luck in your search as well.
The OEM TI systems were fussy which is why I couldn't believe that my car actually started after being put up on blocks for 28 years when I got it running. I would have for sure thought the amp box would be shot but no it all worked and ran. I still have all the TI parts on a shelf as I went with a full MSD system.
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Old Mar 30, 2022 | 12:13 PM
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Originally Posted by Nowhere Man
You can take a standard tach drive dist and make it into a TI. They use the same cast iron body.
NOPE! As I said both my mechanic and the machine shop said it could not be done. I have a freshly rebuilt tach drive distributor for the car and they had both of them side by side. I don’t recall EXACTLY why it could not be done so if you know all the particulars rather than just something you read in a book and can tell me HOW I have to go with what they said.
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