69 z28 frame mounts - Team Camaro Tech
Tech 2000 Our previous General Forum
Replies ONLY - no new topics.

LinkBack Thread Tools Display Modes
post #1 of 11 (permalink) Old Aug 15th, 00, 02:36 PM Thread Starter
Tech Team
Join Date: Dec 1999
Location: E.Moriches,NY,USA
Posts: 41

Hi everyone! Can anyone tell me if I have correct z28 frame to engine mount brackets? The part numbers I have are 3945507 and 3945508. I have heard these are different from other small block mounts. Does anyone now what differences there are? Do I need to order special motor mounts? Thanks in advance.
jacksz28 is offline  
Sponsored Links
post #2 of 11 (permalink) Old Aug 15th, 00, 05:30 PM
Senior Tech
Join Date: Jul 2000
Location: Louisville,KY
Posts: 159

The frame mounts on a normal small block and a Z/28 are the same from what ive seen.But the motor mounts on a Z/28 are diffrent than regular small block but are the same as big block.I have two small block frame mounts i just removed from a subframe and your welcome to them if you think yours are wrong.I cleaned the up a little but can find no numbers on them to check yours.
allcamaro is offline  
post #3 of 11 (permalink) Old Aug 16th, 00, 04:26 AM
Gold Lifetime Member
clill's Avatar
Join Date: Nov 1999
Location: Woodland, Ca.
Posts: 3,533

I have a 69 Z built in LA that I am doing right now with the same frame mount #'s.
clill is offline  
post #4 of 11 (permalink) Old Aug 16th, 00, 06:16 AM
KevinW's Avatar
Join Date: Jul 2000
Location: Millstone, NJ
Posts: 10,994

I have a LA 69 SS 350 and I think I have the 307/327 mounts, based on CRG mount info. If someone finds out where the part numbers are stamped, please let me know. I could not find any either. Thanks, Kevin

69' SS-350 ragtop, M20, 3.55 posi. Totally Disassembled & in boxes (I am working on it!)
KevinW is offline  
post #5 of 11 (permalink) Old Aug 16th, 00, 04:00 PM
Senior Tech
William's Avatar
Join Date: May 2000
Location: Waukesha WI
Posts: 2,938

You have the correct frame brackets. They were used 1969 only for the 302 & 350 engines. They are narrower and shorter than the bracket used for all 67-68 sb and 69 307/327. The problem with them is that either motor mount will fit. If the wrong mount is used on the 302/350 bracket the engine will be too low and can move around, causing driveline vibration and clutch chatter. The correct mount is a tight fit on the frame bracket.

William is offline  
post #6 of 11 (permalink) Old Aug 16th, 00, 05:23 PM Thread Starter
Tech Team
Join Date: Dec 1999
Location: E.Moriches,NY,USA
Posts: 41

William, I can't believe you mentioned that driveline vibration. That was something driving me nuts, a real wicked high frequency vibration in the shifter handle at about 60mph. I wonder if that could be it. I'll have to check the mounts and see if they are for the 302. Any hints or part numbers to differentiate the two? Thanks for all the replies.
jacksz28 is offline  
post #7 of 11 (permalink) Old Aug 16th, 00, 05:44 PM
Tech Team
Join Date: Feb 2000
Location: Little Rock,Arkansas
Posts: 30

Hey guys I just went through this and posted a question a couple of weeks ago about it.
My frame mounts were 3945507 and 3945508 I had bought motor mounts for a 327 thinking all small block frame mounts were the same.
NOT!!!!! The drivers side motor mount bolt went in ,no problem,but the passenger side was off by 1 1/2 inches. After much head scratching and comparison to some big block frame mounts that I had I finally looked in the Classic Industries catalog and saw that they showed frame mounts for a 302-350 a 307-327 and another set for big blocks. They showed that motor mounts were the same for the 302-350 and the big block. After a trip to the local NAPA store and looking at the motor mounts for the big block compared to the motor mount for the 307-327 {there was quite a bit of difference} I bought the big block motor mounts and they fit perfect!!!
Jbboa is offline  
post #8 of 11 (permalink) Old Aug 17th, 00, 03:38 AM Thread Starter
Tech Team
Join Date: Dec 1999
Location: E.Moriches,NY,USA
Posts: 41

What is up with that? Is there a reason for such drastic differences in sb mounting? Is it possible GM might of thought ahead and designed small block brackets to accomodate beefier motor mounts on a high performance engine? Or does the engine position relative to the rest of the car have an effect in HP application. Thanks jbboa.
jacksz28 is offline  
post #9 of 11 (permalink) Old Aug 19th, 00, 04:36 AM
Senior Tech
Join Date: Jul 2000
Location: Caledonia,NY,USA
Posts: 233

The 350 small block perches ant the BB perches are not the same. I had 350's in the car and my motor wouldn't fit. Got the BB one and it fell right in.
69er is offline  
post #10 of 11 (permalink) Old Aug 21st, 00, 05:45 AM
Senior Tech
Join Date: Jan 2000
Location: Chickasha, OK
Posts: 105

The 69 Z28 frame mounts are shorter than the standard SB mounts. I think it is to allow for more hood clearance with the high-rise intake. The bolt hole in the frame mount is slotted too. I have a picture of a 69 Z28 frame mount if anyone wants it, e-mail me and I will send it to you. Take care.

Shane (e-mail address in profile)

69 SSRS Frame-off Resto
81 Z-28 377ci Drag Car
69SSRS is offline  
post #11 of 11 (permalink) Old Aug 21st, 00, 04:29 PM
Gold Lifetime Member
Jonesy's Avatar
Join Date: Oct 1998
Location: Minnesota
Posts: 6,432

Kevin W

The part numbers are stamped clearly on the upper side (the side with 2 bolt holes). 3945507 is drivers side and 3945508 is pass side. I could not read the "7" because it is under one of the nuts on the mount. I have a SS350 and I know for sure these are the original mounts.

William's post above is correct

1969 Camaro RS/SS 350/4spd, Azure Turquoise (55-55)
Van Nuys Built 11B
currently on the rotisserie
1972 Chevelle SS Conv LS3
1984 Z28 w/ZZ4 conversion
Jonesy is offline  
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may not post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome