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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Bobs85PU on March 08, 2013, 09:23:02 pm

Title: ZZ4 Vortec Engine Harmonic Balancer
Post by: Bobs85PU on March 08, 2013, 09:23:02 pm
When I bought my 85 Pickup, it had a ZZ4, roller cam, Vortec engine. As is still had the original EFI Balancer, I had to change it to one with timing marks. Yes, this is a ZZ4 engine...All the numbers (engine and head numbers are correct ZZ4)...It's not an aftermarket engine, but one that was installed in an EFI vehicle.

I never even took into consideration what kind of balancer I installed...a "run of the mill" balancer from NAPA (made in China).

I am now aware of balancers for internal balanced vs externally balanced Vortec 350 engines...what balancer should I be using????

I don't race, so I only need a proper balancer...not a couple hundred dollar model. All this truck is for, is hauling stuff in its bed; and pulling a car hauler trailer.
Title: Re: ZZ4 Vortec Engine Harmonic Balancer
Post by: Fairlane514 on March 09, 2013, 12:09:22 am
It's carbureted I'm guessing?  If so, then just a regular 350 balancer will work,  8 inch. 
Title: Re: ZZ4 Vortec Engine Harmonic Balancer
Post by: Bobs85PU on March 09, 2013, 09:23:51 am
It's carbureted I'm guessing?  If so, then just a regular 350 balancer will work,  8 inch.

Correct...Edelbrock Performer Intake, Electric Choke 600CFM Carb, and HEI Distributor...Along with Coated Headers and matching Exhaust System.

I do have to remove the Distributor and replace the Drive Gear with the correct type.

But I'm still back to the same question...Balancer that is Internal or External balanced?????
Title: Re: ZZ4 Vortec Engine Harmonic Balancer
Post by: Fairlane514 on March 09, 2013, 09:34:07 am
The 400 crankshaft is the only oddball balancer...............so a regular old school 350 balancer will work for you, 8 inch.

Here's one from Summit   SUM-161358
Title: Re: ZZ4 Vortec Engine Harmonic Balancer
Post by: Bobs85PU on March 09, 2013, 05:59:04 pm
Thanks a bunch...I've had this truck a few years, but I'm still learning Chevy engines...last one I worked on was in 1964..I do have one heck of a learning curve to overcome!!!

Flathead Fords and VWs have been my thing over the many years...especially VWs!!!