What is this pair of heads?

Greg Reimer 7376 · 05-04-2024, 05:47 PM

I was rooting around in the chevy. head core department of my stockpile of stuff and came up with two cylinder heads. One of them is a 3946813 number, the other is a 3917 13.The 8 is missing on it. One date code is an E 5 1.The other head is an L 8 0. They are in the classification guide as a legal replacement head for the 327 250 horse head for a '68 Chevelle or big car. I have never seen any other heads with this number, one of them I got off Ebay about 15 years ago, the other one was from a core pile at a local machine shop that is long defunct. The heads I always ran on my Chevelles was a 290 casting, a one year only casting.It only came on '68 327 250 horse engines. Another casting was the 293 casting, and these came on 327 210 horse 2 barrel Camaros only. What is the origins of the 813 head as to its OEM application? I know all these heads are 56 years old by now, but it would be interesting to find out about the OEM application of the 813 castings. Any ideas?

mike britt · 05-04-2024, 08:18 PM

69 to79 350 smog head with 76 cc chambers.

Greg Reimer 7376 · 05-04-2024, 10:12 PM

One thing I forgot to mention in my first post regarding those heads is that they have 1.72" intake valves. I don't know of any 350's with the small intake except a set of truck heads that had 11/32"diameter intake valve stems and 3/8"exhaust stems.That must have been an attempt to stop the excessive valve guide wear caused by the lower lead content of the fuels back then.The 1970's sure were a mess as to the effects of things on the automotive industry.

Adger Smith · 05-08-2024, 05:30 PM

Thanks to Barry Polly
https://www.ncrs.org/ok/LIME_BOOK_2018.pdf

05-04-2024, 05:47 PM	#1
Greg Reimer 7376 VIP Member Join Date: Nov 2008 Location: Glendora,Calif. Posts: 1,115 Likes: 166 Liked 654 Times in 209 Posts	What is this pair of heads? I was rooting around in the chevy. head core department of my stockpile of stuff and came up with two cylinder heads. One of them is a 3946813 number, the other is a 3917 13.The 8 is missing on it. One date code is an E 5 1.The other head is an L 8 0. They are in the classification guide as a legal replacement head for the 327 250 horse head for a '68 Chevelle or big car. I have never seen any other heads with this number, one of them I got off Ebay about 15 years ago, the other one was from a core pile at a local machine shop that is long defunct. The heads I always ran on my Chevelles was a 290 casting, a one year only casting.It only came on '68 327 250 horse engines. Another casting was the 293 casting, and these came on 327 210 horse 2 barrel Camaros only. What is the origins of the 813 head as to its OEM application? I know all these heads are 56 years old by now, but it would be interesting to find out about the OEM application of the 813 castings. Any ideas?

05-04-2024, 08:18 PM	#2
mike britt Member Join Date: Mar 2013 Location: Italy, Texas Posts: 142 Likes: 207 Liked 43 Times in 19 Posts	Re: What is this pair of heads? 69 to79 350 smog head with 76 cc chambers.

05-04-2024, 10:12 PM	#3
Greg Reimer 7376 VIP Member Join Date: Nov 2008 Location: Glendora,Calif. Posts: 1,115 Likes: 166 Liked 654 Times in 209 Posts	Re: What is this pair of heads? One thing I forgot to mention in my first post regarding those heads is that they have 1.72" intake valves. I don't know of any 350's with the small intake except a set of truck heads that had 11/32"diameter intake valve stems and 3/8"exhaust stems.That must have been an attempt to stop the excessive valve guide wear caused by the lower lead content of the fuels back then.The 1970's sure were a mess as to the effects of things on the automotive industry. Last edited by Greg Reimer 7376; 05-04-2024 at 10:16 PM.

05-08-2024, 05:30 PM	#4
Adger Smith VIP Member Join Date: Dec 2001 Location: Texarkana Ark/TX Posts: 2,359 Likes: 443 Liked 684 Times in 266 Posts	Re: What is this pair of heads? Thanks to Barry Polly https://www.ncrs.org/ok/LIME_BOOK_2018.pdf __________________ Adger Smith (Former SS)