Angle plug head question for Joe?

[Terry M.]

Re: Angle plug head question for Joe?

Keep in mind the lead time for magazines like Hot Rod would have been several to 3/4 months back in those primative pre-computer days. I'm not sure it is much different today.

That means those words might have been writen around Christmas 1969 or New Years 1970.

[Michael H.]

Re: Angle plug head question for Joe?

Keep in mind the lead time for magazines like Hot Rod would have been several to 3/4 months back in those primative pre-computer days. I'm not sure it is much different today.

That means those words might have been writen around Christmas 1969 or New Years 1970.

Thanks Terry. That's exactly what I was going to post/say. (late 1970, though)

I vaguely remember that there was a bit of an issue at times getting these new 742 heads (not for me though) when they first appeared on the scene but in general, I think they were readily available by early 1971.

[Duke W.]

Re: Angle plug head question for Joe?

Duke

The 3958604 and 3987376 numbers that you posted are for regular production heads as used on 64 and later hi perf 327's and 350's. Nothing special or HD about these.

You are correct. The very first over the counter angle plug head was a 3965742. It became available some time in 1970 but I believe it was later 1970.

As I said I don't know the casting number for the 604, but the 376 was machined from the 492 casting, and it's my understanding that the 492 casting was only used for service replacement heads. It was never used use for original equipment, but I agree that there was "nothing special" about it that made it better for racing than any OE big port/valve head.

Duke

[Joe L.]

Re: Angle plug head question for Joe?

I think we've narrowed it down further than that. I just dug out a GM price book dated 3 January 1972 and the 3965742 is shown as being available. (to anyone) The GM price to the dealer was exactly $50. each. (no list price shown)

And lets not forget the scan of the GM page I posted way earlier in this thread, dated 16 November of 1970, that shows the 3965742 cyl head.

Michael-----


Yes, the GM #3965742 is listed in the January 3, 1972 Dealer Parts and Accessories Price Book. However, it's not listed in the January 1, 1971 edition of that publication. This means it had to have been released for GMSPO availability sometime during 1971.

The GM #3965742 was discontinued from SERVICE in February, 1975 and replaced by the GM #336746. The fact that it was replaced by the 336746 and not the 3965784 (which was available at that time) implies that the 3965742 was more akin to the 336746 than it was to the 3965784. If that's the case, then I suspect it was based on a PRODUCTION type casting (possibly the same 3991492 as used for the 336746). As I previously mentioned, the 3965784 was based on the non-PRODUCTION-type casting GM #340292. I don't think the 340292 casting would have existed at the time the 3965742 was released.

Otherwise, I know very little about the 3965742 cylinder head. That's why I didn't mention it in my previous post.

[Michael H.]

Re: Angle plug head question for Joe?

Michael-----


Yes, the GM #3965742 is listed in the January 3, 1972 Dealer Parts and Accessories Price Book. However, it's not listed in the January 1, 1971 edition of that publication. This means it had to have been released for GMSPO availability sometime during 1971.

.

Yup, I agree. That's basically what I said in my first few posts. I know, for sure, that the 3965742 was alive and well in early/mid 1971 and became available to the public some time in mid 1971. I had one of the first few sets released.

I quit racing about 1973 so I have no idea what happened after that. I do remember that several versions of the original "relocated spark plug head" were released during the 70's and 80's but I have no info (or interest) in them. I'll leave that part to you guys with the newer parts books etc.

I vaguely remember (after reading a post here) that a "head assembly", complete with valves, springs, retainers etc was floating around about 1972 or 73. Could this have been the 3965784? I don't know but I suppose that's possible. If you have a price book for that era, the cost, compared to the 3965742 may answer the question.

I think I still have the prints for the 3965742.

[Joe L.]

Re: Angle plug head question for Joe?

Yup, I agree. That's basically what I said in my first few posts. I know, for sure, that the 3965742 was alive and well in early/mid 1971 and became available to the public some time in mid 1971. I had one of the first few sets released.

I quit racing about 1973 so I have no idea what happened after that. I do remember that several versions of the original "relocated spark plug head" were released during the 70's and 80's but I have no info (or interest) in them. I'll leave that part to you guys with the newer parts books etc.

I vaguely remember (after reading a post here) that a "head assembly", complete with valves, springs, retainers etc was floating around about 1972 or 73. Could this have been the 3965784? I don't know but I suppose that's possible. If you have a price book for that era, the cost, compared to the 3965742 may answer the question.

I think I still have the prints for the 3965742.

Michael-----


The GM #3965784 was supplied bare. It may have been available under another part number as a complete assembly, but I have no information on that.

In 1975, the GM #3965784 carried a GM list price of $125.00. The GM #336746, which I absolutely know was supplied bare since I purchased a set in 1975, carried a list price of $109.00. The low volume, special 340292 casting the 3965784 was based on probably accounted for the price difference.

[Dick W.]

Re: Angle plug head question for Joe?

When I get time I will remove the valve cover on the '69 Z and look at the casting # and date. I had totally forgotten it had a set of the angle plug heads on it. They were installed shortly after the release of the heads

[Bill M.]

Re: Angle plug head question for Joe?

Thanks Terry. That's exactly what I was going to post/say. (late 1970, though)

I vaguely remember that there was a bit of an issue at times getting these new 742 heads (not for me though) when they first appeared on the scene but in general, I think they were readily available by early 1971.

Terry and Michael:

Another Hot Rod article dated 2/71, p. 122: "the new (angle-plug) head is now sold by Chevy dealers under part no. 3965742."

Sounds like there was a glitch in timing somewhere...maybe the 11/70 Sport Equipment SS was taken by Hot Rod as meaning "come and get 'em!" but they weren't yet available? Dunno.

I don't have any more Hot Rod articles on the subject...