65-67 BB valve cover bolts (lengths)

[Wayne M.]

Changed my gaskets (stock stamped steel valve covers) and realize that my 7 or 8 thread "A" headmark bolts are marginally too short to properly engage the thread holes in the heads. I would assume that 4 turns minimum would be required for proper retention, before torquing. Problem is made worse on a (set-up similar to a '67-up ?) radio car when the two braided shielded ignition wire eyelets are added to the "stack" which already includes the bolt reinforcement. Lesser but similar situation on a '65 with the one bolt that holds the clean (cold) air tube.

I don't have the '67 AIM or judging guide, but looking at the Long Island catalog, they show, for '65-6, all 14 bolts with RBW headmarks.

Then for 1967, it gets complicated .
For no radio all 14 bolts have the same headmark RBW (same length as the ones for '65-6 ?).
Next they show a 10+4 set [RBW + SBC headmarks]; evidently the 4 bolts are for the locations where the plug wire shielding eyelets are held. Can I assume the SBC are the longer ones (how long) ?
Finally, LIC offers a set of 9+5 [RBW + SBC] for air conditioning (and radio, I assume). I'm guessing that with C60, there's one more SBC for something else that attaches under a valve cover bolt.

Anybody know lengths, or # of threads, on these various bolts ?

[Terry M.]

Re: 65-67 BB valve cover bolts (lengths)

Wayne: This may help or confuse the issue, and applies to early C3s. I suspect it is also applicable to some mid-years -- except possibly for the cold air tube you mention -- the reader will have to make that decision for themselves.

Tonawanda installed 14 rocker arm cover bolts -- ALL the same length.

It would not be beyond reason to find one head mark on one side of the engine, and a different head mark on the other. It would also not be beyond reason to find a mix of head marks.

At St Louis, when the spark plug wires were installed on radio equipped cars two bolts on each side were removed and slightly longer bolts installed to accommodate the spark plug grounding details.

As to the head marks: If you believe St Louis installed bolts were made by the same manufacturer as those installed by Tonawanda, then you would believe all the rocker arm fasteners should have the same head mark. Personally I believe my chances are better of winning the lottery, but that is just me.

[Wayne M.]

Re: 65-67 BB valve cover bolts (lengths)

.... It would not be beyond reason to find one head mark on one side of the engine, and a different head mark on the other. It would also not be beyond reason to find a mix of head marks.

At St Louis, when the spark plug wires were installed on radio equipped cars two bolts on each side were removed and slightly longer bolts installed to accommodate the spark plug grounding details. ....

Terry -- I found a non-headmark solution; dug into my parts bins and found these (remember these ? I forget what you even call them) fasteners ? hold-downs ? I might even paint two orange (Tonawanda) and leave 2 chrome (St.Louis)

Seriously, drug out my nut-bolt coffee cans and found at least four bolts that have about 4 threads additional length, which should be good for my purposes.

Thanks

[Keith B.]

Re: 65-67 BB valve cover bolts (lengths)

WAYNE: I just went thru this issue after I rebuilt my L-36 for my 66BB. I went with roller rockers, obviously wanted to keep factory valve covers and had to double up on the Cork-Lam valve gaskets for height. My org "TR" head bolts were too short. Searched everywhere for longer "TR" bolts to no avail......

Found a machinist who took 7 new and longer threads, cut off heads, and then cut of the headmark of my "TR" and precison drilled out and welded the two together. They are incredible strong, so now I have the correct "TR" headmark attached to longer threads. Once in place you never know it........although I know those fine judges will pick up on two cork=lam gaskets.........hope this helps.........k

[Terry M.]

Re: 65-67 BB valve cover bolts (lengths)

Terry -- I found a non-headmark solution; dug into my parts bins and found these (remember these ? I forget what you even call them) fasteners ? hold-downs ? I might even paint two orange (Tonawanda) and leave 2 chrome (St.Louis)

Seriously, drug out my nut-bolt coffee cans and found at least four bolts that have about 4 threads additional length, which should be good for my purposes.

Thanks

Wayne,

I do remember those Looong chrome fasteners, and I still see them on all brands of show cars. I would bet you could get new ones from Summit or Jegs, but you would have t paint the orange ones yourself.

I was hoping someone with a BB in the garage would go out and measure for you. I believe the longer bolts are only 1/16-inch longer -- so you may have found the right ones.

[Wayne M.]

Re: 65-67 BB valve cover bolts (lengths)

it........although I know those fine judges will pick up on two cork=lam gaskets.........hope this helps.........k

Keith -- wow; that's quite a bit of work (but also quite ingenious ). Cork-lam; that's FelPro, eh? (secret Canuck expression).

Here's a comparison of NOS GM silver coated BB gaskets, compared to what I'm installing Mr. Gasket # 177, cork in rubber binder; 3/16" thk. This checks out with caliper measure, and by comparison, the GM's are 1/32nds less.

Hoping now that I'll stop losing more oil down the sides of the engine than past the piston rings .