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GMC V6 and V12 Engines Engine repair and rebuilding

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  #1  
Old December 28th, 2019, 03:55 PM
5Tractorguy 5Tractorguy is offline
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Default Upgrading to HEI on the 5000

Well folks, it's come time to upgrade the '61 to HEI. Ever since I bought this truck I've had issues with power and such. I've narrowed it down to the distributor being the main problem, mechanical advance just isn't working properly.

My question is... will this distributor from Rock Auto work? Skylark 3.8L Distributor (Aside from having to make the bushing). I'd rather buy one complete than piece one together. I assume I'll have to chance the drive gear also?

-Jake

the 61.jpg
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  #2  
Old December 28th, 2019, 05:10 PM
bigblockv6 bigblockv6 is offline
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Default Re: Upgrading to HEI on the 5000

This distributor appears to be the even fire type which will work as long as you do the modifications as installing the custom machined sleeve and use the gear from the original GMC V6 distributor.
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  #3  
Old December 28th, 2019, 07:15 PM
tbucketnut tbucketnut is offline
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Default Re: Upgrading to HEI on the 5000

Jake, like your barn or shop, looks absolutely killer. What is the tower in the back used for? Does it house a gantry?
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1953 Chevrolet 3100
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  #4  
Old December 28th, 2019, 10:16 PM
5Tractorguy 5Tractorguy is offline
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Default Re: Upgrading to HEI on the 5000

Quote:
Originally Posted by bigblockv6 View Post
This distributor appears to be the even fire type which will work as long as you do the modifications as installing the custom machined sleeve and use the gear from the original GMC V6 distributor.
Thanks. I'm going to go ahead and order it. Plan is to get everything rounded up and ready over the winter so when spring comes I can do the conversion.


Quote:
Originally Posted by tbucketnut View Post
Jake, like your barn or shop, looks absolutely killer. What is the tower in the back used for? Does it house a gantry?
Boy I wish it was mine! I ride horses weekly a town over and their barn makes perfect scenery for truck photos... Someday I hope to have a building that nice to work out of.


20190806_173134.jpg
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  #5  
Old January 3rd, 2020, 01:34 AM
1972RedNeck 1972RedNeck is offline
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Default Re: Upgrading to HEI on the 5000

Are you going to build the bushing yourself or have it made? If you are having someone build it and you would get a discount for more than one, I will send you the money for 2...
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  #6  
Old January 3rd, 2020, 12:32 PM
5Tractorguy 5Tractorguy is offline
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Default Re: Upgrading to HEI on the 5000

Quote:
Originally Posted by 1972RedNeck View Post
Are you going to build the bushing yourself or have it made? If you are having someone build it and you would get a discount for more than one, I will send you the money for 2...
I'm going to build the bushing myself. If I go to a machine shop it'll probably cost the same as buying one from Rod Johnson (WE7X on here...). He has them in stock and ready if you need them sooner than later.
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  #7  
Old May 24th, 2020, 12:08 AM
5Tractorguy 5Tractorguy is offline
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Default Re: Upgrading to HEI on the 5000

Update: Did the HEI conversion recently to the 351. Have a couple question for guys that have made the swap...

1) Where did you pull your vacuum from? I ran mine to the back of the original WW carburetor. (Same spot the vac was on the 305 in my pickup).

2) What degree did you set your base timing at (vacuum line unplugged)

3) When you hold a timing light on the engine, does the mark steadily increase, or does it jump up suddenly at around 1000RPM's?

Truck definitely starts faster! Still having power issues, gets a little better as I increase the base timing (now at 10deg). Not knocking yet, but I don't want to get much higher than that. Have a feeling vacuum advance plays a part in what's going on...

IMG_4247.JPG IMG_4248.JPG

IMG_4249.JPG IMG_4250.JPG

IMG_4251.JPG
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  #8  
Old May 24th, 2020, 10:34 AM
James James is offline
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Default Re: Upgrading to HEI on the 5000

Quote:
Originally Posted by 5Tractorguy View Post
1) Where did you pull your vacuum from? I ran mine to the back of the original WW carburetor. (Same spot the vac was on the 305 in my pickup).
The distributor get manifold vacuum. I got mine from the back of the manifold for my power brake conversion. Removed the plug and install a fitting.
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  #9  
Old May 24th, 2020, 12:21 PM
5Tractorguy 5Tractorguy is offline
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Default Re: Upgrading to HEI on the 5000

Quote:
Originally Posted by James View Post
The distributor get manifold vacuum. I got mine from the back of the manifold for my power brake conversion. Removed the plug and install a fitting.
The hydro-vac pulls from that port on mine. Looks like I'll T the fittings on the manifold and run one to the distributor. I have a feeling it isn't getting sufficient vac through the carb.
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  #10  
Old May 29th, 2020, 09:20 PM
James James is offline
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Default Re: Upgrading to HEI on the 5000

Quote:
Originally Posted by James View Post
The distributor get manifold vacuum. I got mine from the back of the manifold for my power brake conversion. Removed the plug and install a fitting.
I am in error. The distributor should get ported vacuum. The HEI should plug into the same place as the original distributor.

Today I had pulled the hose off of the carburetor and only had vacuum when the throttle open.

Sorry for the misinformation.

Today I also check my engine timing, is set to 5° BUDC.
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