Head bolts - L/89 equipped big blocks for 1969

[Steve Antonucci]

Hello,

I'm new to this forum. I'm restoring a 69 L/89 optioned big block and I have
a question ragarding the correct head bolts to use. I have asked numerous
sources this question and answers range all over the place. The year I am
particularly interested in is 1969 ( early build date to be particular ).

Did L/89 ( aluminum head ) big blocks use special head bolts, or did they use
special flat washers under standard head bolts? Some say yes to special bolts,
some say yes to special washers, and still others say no to either.

If either special bolts and/or washers were used, can anyone suggest a source
for purchasing them? I tried Paragon, but they don't have them. If they are
impossible to source, can anyone suggest a good technically correct bolt and/or
washer that I can use?

Steve

[Clem Z.]

Re: Head bolts - L/89 equipped big blocks for 1969

the washer part# is 3899696 which are hardened washers

[Steve Antonucci]

Re: Head bolts - L/89 equipped big blocks for 1969

OK, are these washers: part# is 3899696 available from GM still?
If so, are they correct for the 1969 model year? Anyone have any?

[Clem Z.]

Re: Head bolts - L/89 equipped big blocks for 1969

yes they are still available and you will need to check with the correct number guys to see if they are legal.

[Joe L.]

Re: Head bolts - L/89 equipped big blocks for 1969

Steve-----

GM parts has everything that you need and under the original part numbers:

1) long head bolts------GM #3877669

2) long head bolts------GM #3877668

3) washers--------------GM #3899696

These exact same washers were used for all 67-71 big blocks with aluminum heads. Chevrolet big block aluminum heads bolt seats were cut deeper by the thickness of the washers so that stock big block head bolts would still engage the same thread depth in the block.

The above-referenced head bolts are the original part numbers and conform to the original specs. However, the headmarkings on currently available bolts are slightly different than originals. On the originals, the ends of the "cross" on the bolt head extended all the way to the head perimeter. The "cross" ends on the current bolts are shorter.

[Joe L.]

Correction

Item (1) should have read SHORT head bolts.

[Steve Antonucci]

Re: Head bolts - L/89 equipped big blocks for 1969

OK Joe,

So in conclusion, the head bolts were standard iron head bolts,
but they did use washers? Is that about it? Or did I miss it?

Thanks so much guys! I already love this forum. Details - details !!!

Steve Antonucci

[Joe L.]

Re: Head bolts - L/89 equipped big blocks for 1969

Steve----

They were standard head bolts and the used washers. Iron head engines used the same head bolts without washers.

The only Mark IV big block engine that use different head bolts was the ZL-1. It used slightly longer head bolts for more thread engagement in the block threads. Plus, it used four additional studs for head retention which iron block engines did not use.

[Steve Antonucci]

Re: Head bolts - L/89 equipped big blocks for 1969

Joe,

Thanks a million. You saved me many, many hours of research.
Hope I can do the same some day.

Steve