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-   -   69 Z28 Cylinder Head Question (https://www.yenko.net/forum/showthread.php?t=182478)

CamarosRus 05-31-2025 12:06 AM

69 Z28 Cylinder Head Question
 
A friend in Seattle who owns a HIGH QUALITY Engine Machine Shop asked
me for help.............so Im asking the "Experts" at YENKO.Net


A customer has a 69 z28 camaro. DZ302 engine. The car was made the second week of December 1968

The heads are 186 castings, they have press in rocker studs and are 1.94 1.5 valve sizes.

They have had a valve grind on them but other than the guide knurling they are virgin.

The outer head bolt boss' are chipped up badly and will need welding or head bolt washers.

The date codes jive l 3 8 and l 4 8.

The question I have, is this the proper build for these heads. 1.94 1.5 without studs and plates OR should I make them 202 1.6 with studs with or without plates?

I have seen 186 heads with 202 1.6 with press studs before off a 302 but not like these are.

Any help is appreciated.

Lynn 05-31-2025 01:34 AM

69 Z/28 would be 186 castings, 2.02 / 1.60 valves, pressed in studs and no guide plates.

Those heads with 1.94 valves are not original to the car.

CamarosRus 05-31-2025 05:10 AM

What 1968 "186" Heads had 1.94 Valves ?????????

X66 714 05-31-2025 11:41 AM

"I" would've been the 9th month so that head would've been on an early 1969 engine. 300 hp 350 comes to mind for those heads....Joe

Lynn 05-31-2025 01:13 PM

Perzactly.

More 186 heads had 1.94 valves than 2.02. Most L48 engines had 186 heads. Some had 041. I even tore down an L48 out of a 69 Full Size car that had one of each?

CamarosRus 05-31-2025 03:01 PM

Thanks to all...........I'll relay your thoughts to my machine shop friend.............

It seems strange that somehow incorrect Sept 1968 Heads found their way onto a Dec 68' built 69 Z28

Rsconv68 05-31-2025 11:47 PM

Rus,
Unless the owner of this Z bought it brand new and kept every single receipt, anything is possible.


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