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Discussion Starter · #1 · (Edited)
We're getting on to the tail end of putting together a 66 389 tripower for a 66 goat and now found the distributor we have is pretty rough .
The plate on the distributor does show the correct date so im either going to look into getting it rebuilt or just find another correct distributor.
I started looking on ebay and found that they are selling used distributors "for 398 tripower " for much more money than a correct one for "a 389"
My question :
Is there/was there a difference in the performance of these distributors and/or are they charging that much more money simply because the numbers on the plate may indicate that it was from a tripower motor and not just a plain Jane 389 ?

Also does anyone know a reputable resource for getting them rebuilt?
Although I'm not sure if that's the route I'd want to go as I'm still unsure if the distributor i has is "for 389 tripower" or just for a 389 . We're trying to keep everything as correct as possible.

The numbers on my current distributor are 1111078 delco remy
The engine block itself is a 66 389 but was not an original gto block.
 

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We're getting on to the tail end of putting together a 66 389 tripower for a 66 goat and now found the distributor we have is pretty rough .
The plate on the distributor does show the correct date so im either going to look into getting it rebuilt or just find another correct distributor.
I started looking on ebay and found that they are selling used distributors "for 398 tripower " for much more money than a correct one for "a 389"
My question :
Is there/was there a difference in the performance of these distributors and/or are they charging that much more money simply because the numbers on the plate may indicate that it was from a tripower motor and not just a plain Jane 389 ?

Also does anyone know a reputable resource for getting them rebuilt?
Although I'm not sure if that's the route I'd want to go as I'm still unsure if the distributor i has is "for 389 tripower" or just for a 389 . We're trying to keep everything as correct as possible.

The numbers on my current distributor are 1111078 delco remy
The engine block itself is a 66 389 but was not an original gto block.
My 1966 AMA specs show the 111078 is for the GTO 4 Bbl. 1111079 is shown for the 326 HO - but this same number is used in 1965 GTO, and 1966 B-body 389CI performance engine and 421CI 3 x 2. 1111054 is shown for the 1966 GTO 3 x 2.

If you are rebuilding the engine, I gotta assume you have the Service/Chassis manual to guide you on the engine build. You should find the distributor numbers and specs in the manual.

Why not rebuild the distributor yourself? Not too difficult. As long as the shaft does not wobble in the bushings, it should be good to rebuild. If it wobbles, then you would need a rebuilder to replace these. But, seeing the engine is not original, I would find another distributor, 1965-1970 with points and use it if the bushings are worn out.
 

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Discussion Starter · #4 ·
My 1966 AMA specs show the 111078 is for the GTO 4 Bbl. 1111079 is shown for the 326 HO - but this same number is used in 1965 GTO, and 1966 B-body 389CI performance engine and 421CI 3 x 2. 1111054 is shown for the 1966 GTO 3 x 2.

If you are rebuilding the engine, I gotta assume you have the Service/Chassis manual to guide you on the engine build. You should find the distributor numbers and specs in the manual.

Why not rebuild the distributor yourself? Not too difficult. As long as the shaft does not wobble in the bushings, it should be good to rebuild. If it wobbles, then you would need a rebuilder to replace these. But, seeing the engine is not original, I would find another distributor, 1965-1970 with points and use it if the bushings are worn out.
Ok so a couple things.
Yes I could rebuild this distributor BUT I have the 078 distributor which was for a 4 barrel carbed engine . You're saying the correct number for the distributor on the 66 389 tripower is 054.
BUT here's another but ...the actual car came 4 barrel although I'm putting a tripower in it so now the question becomes is it worth spending upwards of $600 for a correct oem distributor for the 66 389 tripower seeing as the tripower is incorrect for the car anyway?
Also would it make the car worth more money if I put the correct 4 barrell intake and carb on it ? I've already got a beautifuly done tripower and intake set up to the letter
 

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Ok so a couple things.
Yes I could rebuild this distributor BUT I have the 078 distributor which was for a 4 barrel carbed engine . You're saying the correct number for the distributor on the 66 389 tripower is 054.
BUT here's another but ...the actual car came 4 barrel although I'm putting a tripower in it so now the question becomes is it worth spending upwards of $600 for a correct oem distributor for the 66 389 tripower seeing as the tripower is incorrect for the car anyway?
Also would it make the car worth more money if I put the correct 4 barrell intake and carb on it ? I've already got a beautifuly done tripower and intake set up to the letter
No, I would not invest in a correct number stamped distributor as I don't see it adding any value at all unless you were doing a concours restoration. The fact that it does not have its original engine would be a negative against the car in a concours type restoration.

Not having the original engine/trans/rear end as the car had been built with (numbers matching) will not bring the money a numbers matching car does.

However, adding the tri-power will increase value even if it was not original. Most buyers want, look for, a tri-power set-up on the 1964-66 GTO's whether factory or not. If factory, the value goes up moreso because it was a factory tri-powered car. The factory AFB carb & manifold will possibly hurt resale value.

So keep/install the tri-power for sure. (y) The other item that increases value in the resale market is a 4-speed. Same as a tri-power, need not be original or it may have been installed in replacement of a factory HD 3-speed manual trans (4-speed & auto was optional at extra cost), but original 4-speed cars are worth more even if not the original born with trans, and a correct number original 4-speed increases it even more as many cars do not have their born with 4-speeds. So a possible different levels of the car's value with regards to the 4-speed.
 

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Discussion Starter · #6 ·
Makes total sense.
This is a 3 speed stick car with original tranny and rear. Best not to change that to 4 speeed given the whole totality here??
 

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Its a 66 389 engine block but not for gto.
Everything else is correct drivetrain wise
The 3-speed is most likely the Ford "Dearborn" HD fully synchronized 3-speed. Great transmission in my opinion and others. You will never blow it up. It is 1 gear less than the Ford "top loader" 4-speed, very heavy duty. Have had a couple of the 3-speeds and my '68 Lemans had one as original and drove it for years - but now going 5 speed.

The 3-speed can lower value because few want it. The bright side is all the components are there for the 4-speep upgrade. Personally, you don't see may 3-speeds and you don't see them at car shows. I would keep it as it is unique, but not "rare" as in value increasing rare.
 

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Discussion Starter · #12 ·
Another question if you don't mind.
Is there an actual difference in the mechanics of tripower distributor and 4 barrel ?
 

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You're saying "its likely " its the Ford 3 speed.
Is there/was there another option?
What other GM'S that you know of came with that tranny ?
Yes, Ford 3-speed with the parts needed for GM use. Pontiac bellhousings have 2 bolt patterns - one is for the Ford trans.

The other 3 speed option was the Saginaw which is a lighter duty trans and used on column shift cars and I believe the 6 cylinder.

Buick and Olds also used the Ford/GM trans.

The differences in the distributors are the advance curves and maybe the vacuum cannister. The Service Manual will have the differences. Should not be an issue as you will not be using the factory distributor curves/advances unless you plan to keep the factory high compression and use 100+ octane racing gas?

The 1966 GTO used the "093" closed chamber heads and if you want to use pump gas, you want to drop the compression. Closed chamber heads can tolerate a little more compression than later 1968 and up open chamber heads. You may do fine with 9.5 compression and 93 pump gas if the engine is set-up correctly. Generally, to be safe, 9.0 - 9.5 compression is what you want for pump gas. Otherwise you may need octane booster or race gas to prevent detonation - which will damage the engine, or worse.
 

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Discussion Starter · #15 ·
Ok so all it is is the tuning of the curves and not the distributor itself .
This about the same program as a Chevy?
Somewhere around 36* total. Maybe 11 to 14* initial?
 

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Why not reconstruct the merchant yourself? Not excessively troublesome. However long the shaft doesn't wobble in the bushings, it ought to be great to revamp. On the off chance that it wobbles, then, at that point, you would require a rebuilder to supplant these. Be that as it may, seeing the motor isn't unique, I would track down another wholesaler, 1965-1970 with focuses and use it assuming the bushings are exhausted.
 

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Discussion Starter · #17 ·
You're certainly a wealth of information!
Very much appreciated.
Here's another one.
What plugs and wires should I get for the correct look and performance on this engine?
 

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Discussion Starter · #18 ·
Why not reconstruct the merchant yourself? Not excessively troublesome. However long the shaft doesn't wobble in the bushings, it ought to be great to revamp. On the off chance that it wobbles, then, at that point, you would require a rebuilder to supplant these. Be that as it may, seeing the motor isn't unique, I would track down another wholesaler, 1965-1970 with focuses and use it assuming the bushings are exhausted.
I don't think its wobbling. I'll check it out later on . What parts exactly should I get to fix it ?
 

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I don't think its wobbling. I'll check it out later on . What parts exactly should I get to fix it ?
Everything you need to know will be found on this reading list. GET the SERVICE MANUAL!



 

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Al, great advice by the gang. The shaft bushings are rarely worn. If you don’t have excessive side play they should be fine.

Revamping it yourself is easy. Lay it on it’s side on the bench and check the shaft end play with a feeler gauge. Basically you don’t excessive play here either.

The specs are…GM cast Iron Distributor .003 - .007
GM Aluminum distributor .010 - .015

use Hardened shims, like genuine GM shims or Moroso Part number 26140. These are readily available and inexpensive for a pack.
I never get these too tight, and don’t really notice any issues unless it gets way out of spec where it then rides in the cam gear and can cause timing and idle hunting.

I think .010 is good and even close is ok. Put the thin shims in the center.

new quality points and condenser, like blue streak. Then mark the dist gear to the rotor tip, a dot on each so that you replace it the same. Then knock out the roll pin on the gear with a punch pay attention to where your shims are so you replace correctly.

remove the weights and springs, wear safety glasses those springs will go right in your eye.
Take out the points and condenser and then pull the shaft up and out. Clean it all, put light grease, very light on the shaft. And use light oil on the foam pad underneath the base plate. That is lubed so the vacumn advance can move freely and likely has not been lubed in 50 years. Put it all back together,…use new springs form a curve kit.

use Moroso kit #72310 for 1957 to 1975 GM points distributors. I would leave your original GM weights on for now. Try a light and medium spring they don’t have to match.

put the gear on, new cap and rotor, must be in matched set. I like the ones with brass contacts. MSD sells a nice set try JEGS or Summit.

You can get some Lubricam grease for the cam. Again very light. Set the point gap initially with a feeler gauge 16 thousands. Recheck with a dwell meter once attached to engine and started. Once dwell set you can set timing. And you can move on to curve the. Distributor for optimum performance later.

You can do it. Good Luck!
 
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