still need help L 78 head bolts

[Donald S.]

still looking for help on what i should use for head bolts all the long bolts that came out of the engine are flat head with a cross and a small c in one quadrent ... the short bolts are all recessed with a cross and a small m in one quadrent .. would this be correct to have recessed and flat bolts in the same engine .. i have had many bb appart and in my collecion i have no short bolts that are flat they are all recessed .. any help would be an asset as i want to assemble the engine this weekend ... thanks don...

[Joe L.]

Re: still need help L 78 head bolts

still looking for help on what i should use for head bolts all the long bolts that came out of the engine are flat head with a cross and a small c in one quadrent ... the short bolts are all recessed with a cross and a small m in one quadrent .. would this be correct to have recessed and flat bolts in the same engine .. i have had many bb appart and in my collecion i have no short bolts that are flat they are all recessed .. any help would be an asset as i want to assemble the engine this weekend ... thanks don...

Don-----


"C" and "M" were headmarks commonly seen on head bolts of Chevrolet engines in the 60's and 70's. So, your bolts fit that part of the pattern. It's not uncommon, at all, for the different length head bolts found on an engine to have different headmarkings. This is true of both small blocks and big blocks. So, that situation is very consistent with known original engines.

As far as the untrimmed versus trimmed bolts (i.e. "indented" head versus "non-indented" head), I've seen only the untrimmed style on big blocks. However, that does not mean that the trimmed style were not used. In fact, since the manufacturer's headmarkings (i.e. "M" and "C") on your bolts are consistent with those that GM used during the period and generally inconsistent with aftermarket-type bolts, I would say that they are very likely original to the engine.

[Keith B.]

Re: still need help L 78 head bolts

I went out and looked at the head bolts of my 396 as Joe had indicated there are two different kinds of of bolts specifically on opposite sides of the motor. I have indented cross with M on one side and and non indented or flat with the same markings on the drivers side. These are without a doubt original and untouched.

Keith

[Donald S.]

Re: thanks for the help guys *nm*

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[Joel F.]

Re: still need help L 78 head bolts

Sorry to alter the topic a bit, but would you recommend re-using head bolts? I've always heard mixed opinions on this. A nice set of ARP bolts seems like cheap insurance . . . even at the cost of a couple of points (if that?)

[Mark L.]

Re: still need help L 78 head bolts

Sorry to alter the topic a bit, but would you recommend re-using head bolts? I've always heard mixed opinions on this. A nice set of ARP bolts seems like cheap insurance . . . even at the cost of a couple of points (if that?)

Arp bolts will interfere with the stock exhaust manifolds, been there, got the shirt.

[Wayne M.]

Re: still need help L 78 head bolts

... there are two different kinds of of bolts specifically on opposite sides of the motor.
Keith

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Keith --- are you looking only at the short ones, visible externally near the exhaust manifold, when the valve covers are on ? Or, are you refering to all 3 lengths of BB head bolts ?

(Sounds like you have a real nice car)

[Joe L.]

Re: still need help L 78 head bolts

Arp bolts will interfere with the stock exhaust manifolds, been there, got the shirt.

Mark-----

Very slight grinding on the exhaust manifolds solves that problem; no one will ever notice it.

[Keith B.]

Re: still need help L 78 head bolts

only the short ones per your observation