Bolt Requirements - '66 L72

[Gary B.]

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.

Don,

Then Joe Ray's posting is the best advice. Also, when I've made a mistake during judging it can be corrected on the spot if the owner is adequately familiar with the JG and can point to the text in support of the question at hand.

Gary

[Joe L.]

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.

Mike-------


Towne-Robinson (TR) was manufacturing bolts by the MILLIONS. I'm very sure that there were multiple machines and tooling being used and probably even multiple factories. I think the notion that every one of these machines and every set of tooling produced bolts with absolutely identical headmarks is far-fetched. I expect that the reproduction source produces ONE of the "variants" and this "variant" was used on at least some applications during the period. What "variant" was used on any particular car and any particular application? The only way to know that is to have the known-original bolts used on that particular car and that particular application.

[John H.]

Re: Bolt Requirements - '66 L72

Mike-------


Towne-Robinson (TR) was manufacturing bolts by the MILLIONS. I'm very sure that there were multiple machines and tooling being used and probably even multiple factories. I think the notion that every one of these machines and every set of tooling produced bolts with absolutely identical headmarks is far-fetched. I expect that the reproduction source produces ONE of the "variants" and this "variant" was used on at least some applications during the period. What "variant" was used on any particular car and any particular application? The only way to know that is to have the known-original bolts used on that particular car and that particular application.

Joe -

I agree - all of those bolts were produced on hundreds of Fourslides cold-heading/thread-rolling machines that spit out bolts like machine-gun bullets, and there were many sets of bolt-head dies for each machine, as the dies wore and required regular maintenance or replacement. One should not assume that every Towne-Robinson Fourslides machine used EXACTLY the same cold-heading bolt head die detail; high-volume production didn't work that way.

[Bob P.]

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.

I have a RSC and a TR on there now. Don't remember which is which but I didn't have the right length RSC for one side. Will see what they say at nationals!

[Joe L.]

Re: Bolt Requirements - '66 L72

I have a RSC and a TR on there now. Don't remember which is which but I didn't have the right length RSC for one side. Will see what they say at nationals!

Bob-----


It's very common for the thermostat housing to have 2 bolts of different headmarkings. In fact, it's virtually always the case when the bolts are of different lengths. Most of the time, different manufacturers supplied bolts of different lengths. GM was not concerned about having a "matched set" of bolts.

[Donald A.]

Re: Bolt Requirements - '66 L72

As a follow-up on this thread as Bob Puls and I had reported our thermostat housing "TR" bolts were judged incorrect (photos of mine earlier in this thread). I noted a seller on eBay referred to 'thousands of correct bolts available' so I emailed him about these, he has many, and posted some auctions for me, others are there now if anyone interested, just search for RSC bolts. So I have these now just to avoid this question in the future

RSC Thermostat Bolts.jpgRSC Thermostat Bolts 2.jpg

[Joe L.]

Re: Bolt Requirements - '66 L72

As a follow-up on this thread as Bob Puls and I had reported our thermostat housing "TR" bolts were judged incorrect (photos of mine earlier in this thread). I noted a seller on eBay referred to 'thousands of correct bolts available' so I emailed him about these, he has many, and posted some auctions for me, others are there now if anyone interested, just search for RSC bolts. So I have these now just to avoid this question in the future



[ATTACH=CONFIG]53266[/ATTACH][ATTACH=CONFIG]53267[/ATTACH]

Don------


......until you encounter a judge who considers RSC headmarking to be incorrect and only TR to be correct. Don't laugh; it could happen.

In any event, now that you have the RSC headmarking bolts, you can satisfy the judge you encountered, but understand these bolts are no more correct than the TR bolts you had.

[Donald A.]

Re: Bolt Requirements - '66 L72

In any event, now that you have the RSC headmarking bolts, you can satisfy the judge you encountered, but understand these bolts are no more correct than the TR bolts you had.

Yes, I realize that! So I'm gonna put the TR bolts and a 9/16 socket in my glove box

[Bob J.]

Re: Bolt Requirements - '66 L72

I think you're going to get dinged again on the blue gasket.

[Donald A.]

Re: Bolt Requirements - '66 L72

I think you're going to get dinged again on the blue gasket.

Yes that gasket is a definite ding but I can accept that - it just refuses to leak and all the others did!

[John H.]

Re: Bolt Requirements - '66 L72

Yes that gasket is a definite ding but I can accept that - it just refuses to leak and all the others did!

Don -

One of GM's best-kept secrets is their #10105135 thermostat housing gasket - it has a conventional paper/fiber base, with silicone sealing beads molded on both sides, and doesn't look any different than an ordinary gasket when installed - no ugly blue tipoff to an aftermarket part, and they don't leak.


ThermGsktGM10105135_800.JPG

[Rich P.]

Re: Bolt Requirements - '66 L72

In reference to the multiple TR headmarking...yes I have at least 15 different fonts for originals, But the bolts in the first photo are of first generation repors. Since then some have made closer attempts but still easily identified by a sharp judge. As for TR's being an incorrect headmarking for a 67 660 thermostat housing...just silly!!!