Reply
 
Thread Tools Display Modes
  #1  
Old 06-16-2010, 10:07 AM
Exit32 Exit32 is offline
Junior Member
 
Join Date: Mar 2009
Location: near Boston, Mass.
Posts: 13
Question Longer head bolts needed for A/C bracket on '66 389 engine?

I yanked the ol' 389 out of my 1966 GTO convertible and intend to restore it to its original configuration. I've been gathering parts for years and plan to install:

- 093 cylinder heads
- Correct camshaft (GM 9779068) & lifters
- Correct timing chain cover (GM 9783130)
- Tri-power intake & carbs (thanks, pontiactripower.com)
- A/C system brackets and compressor (no A/C stuff on engine now)

I have questions about cylinder head bolts:

1. Can I re-use the existing head bolts (092 heads on engine now) or do I need to buy new bolts?

2. The A/C bracket (GM 9788304) attaches to engine using two cylinder head bolts. Do I need two longer bolts to accommodate the bracket?

3. If new bolts or longer bolts are needed, what should I get and where's the best place to buy them?

I look forward to your guidance and appreciate all advice!

  #2  
Old 06-16-2010, 06:38 PM
6 Grrrs's Avatar
6 Grrrs 6 Grrrs is offline
Ultimate Warrior
 
Join Date: Dec 2006
Location: Greensburg, PA
Posts: 1,681
Default

The original two bolts have studs on top of them. If you are doing a stock rebuild then you should have no trouble re using them.

__________________
Tod Hoffmann

1966 GTO Montero Red Hardtop - Holley EFI'd 462, KRE DPorts/Muncie 4spd
1990 Chevy 454SS pickup - Accel DFI/T56 6spd - Hot Rod Power Tour Long Hauler
1996 Chevy K2500 ECSB 'Poopy'
2002 Honda VTX1800C
2016 Cadillac CTS Premium

My project thread: http://forums.maxperformanceinc.com/...d.php?t=516826

  #3  
Old 06-16-2010, 07:48 PM
Exit32 Exit32 is offline
Junior Member
 
Join Date: Mar 2009
Location: near Boston, Mass.
Posts: 13
Default

I think you and I are talking about two different A/C brackets, Tod. The bracket that I want to attach to my 389 is a heavy, forged part. The bracket's bolt holes are 1/2-inch diameter -- exactly as needed to accommodate an actual head bolt; not a smaller stud.

I measured the depth of the mounting holes on the bracket. The front hole is 1 inch deep and the rear hole is 2 inches deep. It's now obvious to me that my existing head bolts are way too short to mount this bracket. If I can't locate the correct Pontiac head bolts, guess I'll buy a couple of Grade 8 bolts. You'd have to look hard to see them after the A/C compressor is mounted on the bracket.

Here are a couple of pics that show the A/C bracket I'm talking about:






  #4  
Old 06-16-2010, 10:40 PM
FFD FFD is offline
Member
 
Join Date: Jul 2005
Posts: 71
Default

What he's saying about the bolts is the head will bottom on the bracket just like a regular bolt. But have a stud on the head for what ever reason like many other bolts on these engines. I took that bracket off mine and went looking for shorter bolts. I'll take a look tomarow if I can hunt them up easy you can have them for the amount of shipping if you still need or want

  #5  
Old 06-16-2010, 11:12 PM
6 Grrrs's Avatar
6 Grrrs 6 Grrrs is offline
Ultimate Warrior
 
Join Date: Dec 2006
Location: Greensburg, PA
Posts: 1,681
Default

Sorry for my earlier post. They are not studs. They are 4 5/8" in length. I pulled out my a/c brackets and took these two photos:





Goto: http://www.inlinetube.com/ and look at the GTO Catalog on page 10. They have all of the A/C compressor bolts listed, but these long head bolts. Maybe they have access to the longer head bolts. I'm sure that someone on here will have them if they are not available from the repro companies.

Again - sorry for the bad info posted earlier.

__________________
Tod Hoffmann

1966 GTO Montero Red Hardtop - Holley EFI'd 462, KRE DPorts/Muncie 4spd
1990 Chevy 454SS pickup - Accel DFI/T56 6spd - Hot Rod Power Tour Long Hauler
1996 Chevy K2500 ECSB 'Poopy'
2002 Honda VTX1800C
2016 Cadillac CTS Premium

My project thread: http://forums.maxperformanceinc.com/...d.php?t=516826


Last edited by 6 Grrrs; 06-16-2010 at 11:37 PM.
  #6  
Old 06-17-2010, 08:05 AM
ryan389 ryan389 is offline
Senior Chief
 
Join Date: Dec 2003
Posts: 362
Default

I HAVE EXACTLY WHAT YOU NEED.
ONE OF THE BOLTS HAS A THREADED STUD ON IT.
I WILL POST A PICTURE LATER.

  #7  
Old 06-17-2010, 08:49 AM
ctgross ctgross is offline
Ultimate Warrior
 
Join Date: Feb 2002
Location: Hot Springs, Ar.
Posts: 1,123
Default

I just looked at my car (66 w/fac. a/c) and the rear bolt on that bracket does have the stud on top. Nothing attached to it..maybe they were to be used for other mounting of equip.? Calif. AIR, etc.?

__________________
CT Gross---66 GTO

"Its never too late to have a happy childhood"!

I told my dad I was going to stop raising hell, and he called me a quitter!
  #8  
Old 06-17-2010, 09:28 AM
Exit32 Exit32 is offline
Junior Member
 
Join Date: Mar 2009
Location: near Boston, Mass.
Posts: 13
Default

Thanks for all the replies here. I should have taken a closer look at the A/C bracket before I posted my questions because it's very obvious that I need some longer bolts to make this work.

I really appreciate the photos you posted, Tod. Very helpful. Now that I know that bolt length is 4-5/8 inches. I can get a couple of Grade 8 bolts locally, or buy Pontiac bolts from someone here.

I'll be assembling the engine over the next week or two, so if FFD or ryan389 has the correct Pontiac bolts, let's make a deal.

  #9  
Old 06-17-2010, 05:52 PM
ryan389 ryan389 is offline
Senior Chief
 
Join Date: Dec 2003
Posts: 362
Default Long Head Bolts

Exit32: Here are the pictures that I promised you. Let me know if this is what you want. PM me or post a reply on this thread.

Thanks.
Attached Thumbnails
Click image for larger version

Name:	CIMG4427.jpg
Views:	90
Size:	56.7 KB
ID:	209365   Click image for larger version

Name:	CIMG4428.jpg
Views:	58
Size:	51.4 KB
ID:	209366  

  #10  
Old 06-17-2010, 06:29 PM
Exit32 Exit32 is offline
Junior Member
 
Join Date: Mar 2009
Location: near Boston, Mass.
Posts: 13
Default

Thanks for the pics, ryan389. I sent a PM to you.

  #11  
Old 06-18-2010, 05:23 PM
FFD FFD is offline
Member
 
Join Date: Jul 2005
Posts: 71
Default

Found mine in the bracket box. Little bit different than Ryans. Stud bolt the same the other has an extended head a inch or so with a tapped hole with bolt. Where the dip stick tube bolted to. Talked to someone else said possible from a 68 set up

  #12  
Old 06-18-2010, 09:26 PM
Exit32 Exit32 is offline
Junior Member
 
Join Date: Mar 2009
Location: near Boston, Mass.
Posts: 13
Default

Quote:
Originally Posted by FFD View Post
Found mine in the bracket box. Little bit different than Ryans. Stud bolt the same the other has an extended head a inch or so with a tapped hole with bolt. Where the dip stick tube bolted to. Talked to someone else said possible from a 68 set up
Thanks for looking at your bolts, FFD. I made a deal with ryan389, and I'm good to go with a couple of long head bolts on the way.

I appreciate all the replies and info here. Chances are good that I'll have more questions for you experts as I restore my 389 to its factory configuration.

Reply


Posting Rules
You may not post new threads
You may not 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

Forum Jump


All times are GMT -4. The time now is 12:22 PM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017