I was hoping some of you could help me in identifying the correct mounting bolts for a couple of parts on my '66 L72. I need to know what the head marking requirements are for the bolts on the thermostat housing and the mounting bolts for my transistor ignition amplifier. I presently have "TR" bolts in these locations, but they were judged to be incorrect. These are current replace bolts, so maybe that is the issue?? If you could provide pictures of the correct bolts I would appreciate it. Thanks for your help!
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Bob Puls, 30633 -
Re: Bolt Requirements - '66 L72
Hi Bob, my L72 thermostat bolts are "TR" with three lines. The judging guide says typical bolts for the thermostat housing are as follows: Long Bolts RSC, CP, RBW, TR or O, with three lines radiating out from the center. Short bolts are SBC, A, RBW, RSC, or TR, again with three lines out from the center. They also say "Others may exist." My TI amp has TR bolts but I got them from Long Island last year so not originals!
Thermostat1.jpgThermostat Bolt.jpg -
Re: Bolt Requirements - '66 L72
You have exactly what I have, but the judges didn't like it?Bob Puls, 30633Comment
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Re: Bolt Requirements - '66 L72
Bob----
It won't be the first time something like this has happened. Some judges have "tunnel vision" and consider only certain headmarkings to be correct, perhaps what they've seen on "Survivor" or other known-original cars. With the vast majority of bolt applications, multiple suppliers (and consequently headmarkings) were used. The only commonality for these thermostat housing bolts is that they all should have been GM 280-M material grade (i.e. 3 radial lines).
Very often, the two thermostat housing bolts, which were of different lengths, had different headmarkings. That may be what a judge was looking for. However, that was not necessarily the case and it was quite possible that both bolts would have the same manufacturer's headmarking.
Especially for common hex bolts like the thermostat housing bolts, judges should accept just about any period-correct headmarking (e.g. "TR").In Appreciation of John HinckleyComment
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Re: Bolt Requirements - '66 L72
Thanks for your help Joe. I have a friend who had an unrestored '66 big block that was produced about 1 month before mine and the long bolt was a grade 5 with a P head marking and the small bolt had a WB head marking with no lines at all. Neither of these are in the manual.What do you know about the bolts for the TI AMP?Bob Puls, 30633Comment
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Re: Bolt Requirements - '66 L72
Bob------
I'm not sure what the TI amplifier retaining bolts' headmarking was and, possibly, there was more than one. However, once again, I would think that judges should accept any period-correct headmarking.
With regard to the "WB" bolt with no grade markings, I have noted over the years that "WB" (the headmarking for Wales-Beech Co.) often do not have grade markings even though the bolts are definitely not grade 2 (i.e. normally without any grade markings). I don't know how Wales-Beech got away with this. Perhaps they had some other way of identifying the material grade.In Appreciation of John HinckleyComment
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Re: Bolt Requirements - '66 L72
Unless of course your TR bolts are different from original TR bolts. An example of this is the repro M head mark bolts for C2 bumpers. The repro M bolts don't use the same font as the original M bolts. The center leg in the repro M does not descend to the baseline as it does on original M bolts. Knowledgeable judges know the difference between repro Ms and original Ms. Maybe the same is true for the TRs you're talking about and this could explain the deduct. Of course, if that's the case then that explanation should be explicitly stated by the judges in the comments line on the judging sheet.
GaryComment
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Re: Bolt Requirements - '66 L72
Well to Bob and others I just had the judges also say my TR 3-line thermostat housing bolts were incorrect (photos post #2 above). I asked what would be correct and was told RSC bolts. Again, JG says multiple correct answers. Hmmm.Comment
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Re: Bolt Requirements - '66 L72
Don,
Apart from a judging error, the only thing I can think it that the head mark on repro TR bolts is incorrect in some obvious way. If that's not the case, then the judges did not judge in a way that is consistent with the latest '66 TIM&JG. If that happens again, I suggest you politely point out the content in the JG to the judges.
GaryComment
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Re: Bolt Requirements - '66 L72
Don,
Appeals to judging should be addressed to, the judges, the team leader and then the National Judging Chairman! By then the wheels should be in motion to change your score or change the judging manual. I'm sure that with our new National Judging Chairman and new President the wheels are in motion to take care of errors by judges and judging manuals.
Just to be sure that is called confidence in our elected officials and not being critical of the system. The system works!
JRComment
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Re: Bolt Requirements - '66 L72
Bob,
Here's a close-up photo of an original grade 5, TR headmark bolt. In terms of the font style, do the repros you used look exactly this one?
Gary
Grade 5 TR.jpgComment
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Re: Bolt Requirements - '66 L72
Yes, and I posted above photos (post #2) but here is a closer up of that photo of my thermostat.bolt.jpgComment
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Re: Bolt Requirements - '66 L72
Look at the thickness of the bars radiating from the TR on the one Gary posted vs. yours. Look at the relationship of the top letters to the upper bar, and the right leg of the R in relationship to the lower right bar. Your pair scream "reproduction" to my eyes. I have a number of original M bolts, and they look much more like Gary's than yours.Comment
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Re: Bolt Requirements - '66 L72
Well yes, they may well be reproduction bolts, but my question was regarding TR marking. I was told the bolts were incorrect, should be RSC bolts. I did not lose points for reproduction bolts but for wrong bolts.Comment
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