67 BB Head Bolts

**Joe L.** · April 30, 2020, 08:00 PM

Re: 67 BB Head Bolts

Originally posted by Daniel Edmond (43962)

All,

I am beginning reassembly of my 427 390HP engine and would like to use 'correct' head bolts. I searched the archives and found the bolts should have a recessed head, a plus (+) and a letter in one of the plus (+) quadrants. I have the following which appear to 'match' that description but are they typical for the 1967 production year? Could someone post a photo of a known original?

[ATTACH=CONFIG]98654[/ATTACH][ATTACH=CONFIG]98655[/ATTACH]

Thanks
Daniel

Daniel------

First of all, I can't tell you what headmarking is typical for 1967 big blocks. But, I can tell you this: head bolts are critical fasteners. I'd be very reluctant to re-use any head bolts of unknown history. If a bolt was known to be first-run (i.e. from a factory assembled engine that had never previously been apart) AND there was absolutely no damage to any part of the bolt then I MIGHT be inclined to re-use it. Otherwise, HIGH QUALITY NEW only.

**Daniel E.** · April 30, 2020, 08:09 PM

Re: 67 BB Head Bolts

Thanks Joe. I never thought about them as critical. I guess a reproduction set is in my future.

**Larry M.** · April 30, 2020, 08:23 PM

Re: 67 BB Head Bolts

Originally posted by Daniel Edmond (43962)

Thanks Joe. I never thought about them as critical. I guess a reproduction set is in my future.

Reproduction may be the worst choice. Use ARP like most of the builders.

Larry

**Doug M.** · May 1, 2020, 09:52 AM

Re: 67 BB Head Bolts

Daniel,
FYI, but if you use ARP 135-3601 head bolts, you may have to eliminate the washer on the short bolts. Using the supplied washer
creates a taller bolt head than stock, your exhaust manifolds may not line up.
Also, be aware that the middle row is visible if you are having your car judged using bolts from this kit.

Doug

**Patrick B.** · May 1, 2020, 10:12 AM

Re: 67 BB Head Bolts

The only big block bolts I have had trouble with are the early 65-66 main cap bolts having the windage tray standoffs with female threads. I have never had an issue with used head bolts, but I would not use a corroded or beat up bolt. If the bolt torques up quickly with no sign of yielding, I would not fear it. One approach would be to use new ARP bolts for the bolts under the valve cover and used original short bolts that show and may be critical to exhaust manifold clearance.

**Daniel E.** · May 1, 2020, 12:27 PM

Re: 67 BB Head Bolts

Doug,

Thanks for those details. I was looking at the ARP bolt kits and noticed the washers. Had me wondering if they were necessary on cast iron head or only aluminum heads.

Daniel.

**Daniel E.** · May 1, 2020, 12:32 PM

**Keith B.** · May 1, 2020, 01:08 PM

Re: 67 BB Head Bolts

Daniel there was many suppliers for head bolts. AMK is a good source for reproduction bolts

**Mike B.** · May 1, 2020, 01:37 PM

Re: 67 BB Head Bolts

Daniel,

I've replated my 427's original head bolts with full intentions of using them again. I recognize all the headmarks that you've shown in your photos. I've discussed reusing them on my 942 L-36 block's rebuild.

Pat's advice here is sound and I may only use the ones that are visible outside of the valve covers. Fresh ARP bolts under the covers.

I know you are asking about head bolts here but let's show everyone reading of what Pat is describing about the trouble of reusing original '65-'66 main cap bolts with the tall windage tray standoffs. When I was disassembling my 390 hp 2 bolt main block's caps check out the 2 bolts that snapped in two. These bolts snapped with ease and felt very brittle. Luckily, when the caps were removed there was enough bolt shaft remaining to remove them. Beware. Only fresh bolts under the pan for my engine's rebuild! Mike

'66 427 Snapped Windage Tray Cap Bolts (1).jpg '66 427 Snapped Windage Tray Cap Bolts (2).jpg '66 427 Snapped Windage Tray Cap Bolts (3).jpg

**Patrick B.** · May 1, 2020, 04:32 PM

Re: 67 BB Head Bolts

Yes Mike, those are the bolts I was referring to. I would never use one of those even if it were in a NOS package. I have never had any trouble reusing the regular maincap bolts though.

**Joe L.** · May 1, 2020, 04:55 PM

Re: 67 BB Head Bolts

Mike------

If you've re-plated the original bolts that adds more uncertainty. If you've used any kind of electroplating process, that results in hydrogen embrittlement. Any such plated parts must be properly heat-treated after plating to remove the hydrogen. Even if you've just re-phosphated them without any electro-process, this can result in hydrogen embrittlement. If it were me, either way I would not be comfortable using them. But, to each his own.

As far as the main caps studs go, the original studs were GM #3866372. These were discontinued in October, 1967 and replaced by GM #3902885. The latter was used in PRODUCTION for 1968-74 big blocks and may also have been used for late 1967. GM did not go to the 3902885 because the 3866372 worked just as good.

**Mike B.** · May 1, 2020, 05:19 PM

Re: 67 BB Head Bolts

Pat, I remember we discussed what happened to my windage tray bolts way back. Won't be using those again!

Joe, Yeah we used a kit that involved boiling the bolts in a solution that turned them black. No electrolysis involved. But the subject of hydrogen embrittlement has definitely come up. I'll be digging deep into the subject before I use any of those. Probably won't. Too paranoid now. Don't know why I even bothered. They were fine the way they were. Just minor surface rust that brushed right off. Live and learn.

Mike

**Daniel E.** · May 1, 2020, 06:00 PM

Re: 67 BB Head Bolts

Pat,

Are you suggesting to eliminate the windage tray? If you aren’t, what manufacturer replacement bolts should I purchase to allow the windage tray to be reinstalled?

Comment: I did some more research and understand what you mean. Don’t use the early bolts but the use of 3902885 is okay.

Thanks
Daniel

**Patrick B.** · May 1, 2020, 07:44 PM

Re: 67 BB Head Bolts