Messages

The 1967-1969 Z28 Holley carburetor database has been completed, with many thanks to both Jerry MacNeish, of Camaro Hi-Performance, and Ben Wenzel, owner of the famous 1967 Z28 NHRA C-Stock race car -- the first Camaro ever to set an NHRA national record, who made their 1967 List 3910 and 3911 Holleys available to me.  And thanks to CRG Core Members Kurt Sonen and Bryon Miller for their support in publishing it.  The database is posted in the Reports section of the website.  It can be accessed by visiting either the "The First-Generation Camaro Z28" report, or the "First-Generation Camaro Carburetors" report and clicking on the "more on Z28 carb specs at this link" that appears in each of these reports.

The 1967-1969 Z28 Holley carburetor database has been completed, with many thanks to both Jerry MacNeish, of Camaro Hi-Performance, and Ben Wenzel, owner of the famous 1967 Z28 NHRA C-Stock race car -- the first Camaro ever to set an NHRA national record, who made their 1967 List 3910 and 3911 Holleys available to me.  And thanks to CRG Core Members Kurt Sonen and Bryon Miller for their support in publishing it.  The database is posted in the Reports section of the website.  It can be accessed by visiting either the "The First-Generation Camaro Z28" report, or the "First-Generation Camaro Carburetors" report and clicking on the "more on Z28 carb specs at this link" that appears in each of these reports.

If your speedometer needs service, it can easily be removed without having to remove the dash pad, possibly dropping the steering column an inch or so, unplugging numerous wiring connectors and removing the entire Speedo/Fuel/Clock/Tach gauge cluster as a unit.

For safety, before starting, disconnect a battery cable.  Next, remove the four Phillips head screws holding the speedo's lens cover to the dash (two at the top of the lens cover and two below the bottom of the lens cover, where the wiper switch is located). Then, to disconnect the speedo cable, reach your hand behind the dash from underneath -- the speedo cable is inserted into the back of the speedo and a small circular spring clip around the cable's end fitting holds it in place.  Depress the spring clip with your thumb and pull the cable out of the speedo. Next, reach up under the dash and remove the two ¼" hex head screws, one on either side of the mechanism, that hold the speedo to the gauge cluster.  I suggest using a very small box end wrench – an ignition wrench is ideal.  Be careful not to disturb or lose the small rubber isolator around each screw.  They may or may not come out with the screw – mine did not.  Once these two screws are out, gently push on the back side of the speedo to move it slightly rearward, just far enough to get your fingers around the edge of the gauge's face to lift it out. You don't want to push it too far rearward so that the speedo falls out. The face and needle are fragile and can get damaged.

The entire removal operation was surprisingly easy and very straightforward.  It took less than 10 minutes from start to finish, without any undo contortions, effort or surprises.  For some folks, it may help to remove the driver's seat to allow a more comfortable lying down position, flat on the floor, when reaching up behind the dash to access the cable connection and the two ¼" hex head screws.  I'm 75 yrs old and in reasonable shape and didn't remove the driver's seat.  I kneeled on a cushion on the garage floor and leaned in to stick my head a bit under the dash.

This would be a good time to check/replace any missing or failed turn signal or indicator lightbulbs that are now exposed by having removed the lens cover.  Check the lightbulbs under fuel gauge/tach lens cover, too.

A friend of mine sent his '68 Firebird IP gauges to Pete Serio for restoration/calibration fall.  I also had Pete do some work for me about 2 years ago.  The last time my friend heard from Pete was this past June.  Since then, there has been no response to emails or anyone answering the phone.  Does anyone know if anything has happened to Pete?

That about wraps it up -- thanks Kurt and Bryon.

Encouraging info -- thanks to all who responded.  A friend took my question to a Corvette forum and received very similar responses to those here.

What about the possibility of the new-for-1969 head casting p/n 3927186 being introduced early, as a running change during the last 3-4 months of the '68 model year?  If introduced early, and if Flint didn't spend tooling $'s for drilling/tapping the alternator mounting holes, were these new head castings ever used on later '68 engines with their left side alternator mounting provision remaining in place until the actual 1969 start of production, when the change over to the right side alternator location took place?

If that is unlikely (or never documented by anyone in CRG as having taken place on an engine), I would have to agree it is most likely explained by a digit that got "buggered up" a bit during the mold making/casting process.

My 05E Norwood '69 Z28 has a pair of the 3927186 cylinder heads on its engine and both heads have the bosses and 3 drilled/tapped holes for a right side alternator mounting location that was adopted for the start of the '69 model year.  Right side head has a casting date code of E79 (May 7, '69).  Left side head date code looks much more like E78 (May 7, '68) than it does E79 -- see photos.  The engine build date per my P-O-P is 0513 (May 13th).

Has anyone observed a 3927186 head with a casting date as early as May 7 of 1968?

August 2026 Update:

While having my '69 Z28 certified/appraised at Jerry MacNeish's shop in Maryland last month, he had laid out a couple of his original '67 Z28 Holley List 3910 carbs (date codes 751 and 753) for me to measure various air/fuel calibration hole diameters (PVCR, IFR, etc.) -- info I was missing in my database of the three different Holley carbs used on '67-'69 Z28's.  That completes the list of all calibration spec's on two of the three unique carbs for these engines, the '67 List 3910 and the '68 & '69 List 4053.

Jerry also gave me contact info for someone he knows very well who owns one of the incredibly scarce Holley List 3911 carbs that came only on the few '67 Z28's built for sale in California.  I've contacted that person, who luckily lives only about an hour and a half from me, and he agreed to let me review that carb once we agree on a mutually acceptable date sometime in the next few months.

Stay tuned!

August 2026 Update:

While having my '69 Z28 certified/appraised at Jerry MacNeish's shop in Maryland last month, he had laid out a couple of his original '67 Z28 Holley List 3910 carbs (date codes 751 and 753) for me to measure various air/fuel calibration hole diameters (PVCR, IFR, etc.) -- info I was missing in my database of the three different Holley carbs used on '67-'69 Z28's.  That completes the list of all calibration spec's on two of the three unique carbs for these engines, the '67 List 3910 and the '68 & '69 List 4053.

Jerry also gave me contact info for someone he knows very well who owns one of the incredibly scarce Holley List 3911 carbs that came only on the few '67 Z28's built for sale in California.  I've contacted that person, who luckily lives only about an hour and a half from me, and he agreed to let me review that carb once we agree on a mutually acceptable date sometime in the next few months.

Stay tuned!

I found this one, loose, hex head screw wedged between the upper rounded edge of the washer reservoir and the  radiator closure panel on my '69 Z28.  It's 1/4"-20, non-full thread, 7/16" hex head, 13/16" long with a small hole drilled through each flat on the hex and a larger dia. blind hole, about 1/8" deep, in the center of the head.  Anyone recognize it as a legit Camaro fastener?

At first blush, it resembles the two fasteners that attach the left side radiator support to the radiator closure panel, into well-nuts, but the those screws have a flange head and do not have their hex flats thru-drilled, per the AMK website -- unless I'm wrong about that.

Thanks for the help.

Thank you!

That's one less thing to do (three times!) for my trip to and from the Camaro Nat's in Morgantown, PA, next week, with a side trip on the way home to Jerry MacNeish's shop in Maryland for an appraisal/certification.

I will be trailering my '69 Z28 in an enclosed trailer very soon.  Although I am an experienced trailer user (boats, 5th wheels, utility, etc.), this will be my first time using an enclosed car hauling trailer.  The trailer has an electric winch to pull the car into the trailer, rather than having to drive the car in.  I plan to attach the winch cable to an axle strap looped around the center of the front suspension crossmember and then pull the car up the ramp with the winch.  I'm hoping others have determined if it is advisable to remove the front spoiler and support rods before loading the car into the trailer. 

If I don't remove the spoiler and support rods, is it possible these parts would contact the loading ramp's surface as the car begins to make its way up the ramp?

Thanks for your help.

Thanks Jim.

Does anyone know the hex size and thickness of the pair of 5/16"-18 adjusting nuts (GM #9417954) on the front parking brake cable?

Are they the standard 1/2" hex for a 5/16"-18 nut or are they the oversize 9/16" hex?

They could also be thicker than a standard nut to permit an open end wrench to hold the one nut (the nut that is against the cable guide) while the 2nd (locking) nut is tightened.

Also, I've found conflicting info on whether these nuts are phos/oil coated or zinc plated.

Thanks for the help.

Like many before me, the correct speedo cable clip is a difficult part to find.  Some cars have 2 holes in the tunnel and use 2 clips in the tunnel area, while others have one hole in the tunnel.  In addition, there is a hole behind the ignition coil on all cars for another clip, close to the cable's grommet, just before where the cable enters inside the car.

One restoration parts supplier offers two versions of this clip p/n 3772324, one of which is described as "assembly line correct" at a higher price.  I've tried installing this "assembly line correct" clip and find that one of the short locking fingers breaks off when trying to get it into the sheet metal hole and/or when expanding the locking fingers.  This happened with two of these clips.  Reviewing posts from others on these clips, it is apparent no one is making a workable version of it.

In the meantime, I've found another style clip that does a great job of supporting the speedo cable, in any of the 2 or 3 locations for a speedo clip and securely fits into the existing approx 5/16" drilled hole in the sheet metal.  The clip I found is actually a MoPar brake line clip for use with armored brake tubing (measures approx. 5/16" dia. over the armor/spring material).  It was used extensively on 1960's and early 70's MoPar cars.  This clip not only fits the existing sheet metal hole nicely, but also gives a secure fit to the Camaro's speedo cable.

Until such time as I can find the correct style Chevy clip that actually installs, expands the locking fingers properly without them breaking off, and stays put, this MoPar clip is going to be used to keep the speedo cable properly routed.  They are available from any of the MoPar restoration parts suppliers.