1969 Double Hump Head Question
Thread Starter
Instructor
Joined: Sep 2000
Posts: 187
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From: Flagler Beach, FL
1969 Double Hump Head Question
I just found out that my 1969 350/300hp does not have matching heads. I would like to make a matching set before having them rebuilt. Can someone tell me if both the "186" and the "492" heads were both used in 1969. I have one of each. Thanks!
Instructor
Joined: Nov 2003
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From: Rockingham NC
Re: 1969 Double Hump Head Question (Revman)
I know for sure the 186 head was right for yours, but there is a lot of discussion on the 492. Most say it was not out until early 1970. I have had some tell me it was on a 69?? Im sure some of the real good experts will chime in. I think the 492 was a 1970 head though.
Intermediate
Joined: Feb 2002
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From: Odessa FL
Re: 1969 Double Hump Head Question (brs6482)
You sure about it being a 492 head. I think my double hump heads are 462 heads and have been around since the 60's. They are also referred to as fuelie heads.
Thread Starter
Instructor
Joined: Sep 2000
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From: Flagler Beach, FL
Re: 1969 Double Hump Head Question (Resto75)
I am pretty sure about the 492, the number appears to read 399492, although those numbers are sometimes a little hard to distinguish.
Instructor
Joined: Nov 2003
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From: Rockingham NC
Re: 1969 Double Hump Head Question (Resto75)
The 462 has the big double humps, the 492 has the small humps like the 186 head. You are correct in the 462 being around for a while but i believe the 492 came out in 70
Racer
Joined: Dec 2003
Posts: 257
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From: Livermore CA
Re: 1969 Double Hump Head Question (Revman)
According to my info the 492 head was put in service replacing the 186 head after the earliset date of 10/9/70. So the head is not correct for a 1969. You can check the date code cast into every head, it's on top with a letter for the month A= Jan, then the date of the month, and the last number indicates the year 9=1969 (on a 186 head or maybe 1979 on other heads) You have to be aware of the casting numbers for the date (casting numbers were only used for a limited time) beacause with GM only using 1 number for the year it could be from different decades. To find the correct head for your car look for a 186 or possibily a 041 (they were interchangable during 1969) the the correct date code (usually a window of a max of 6 months before the date code stamped onto your engines front stamp pad)
Hope this helps you
Jeff
Hope this helps you
Jeff
Emerging Vendor
Joined: Mar 1999
Posts: 1,599
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From: San Diego CA
Re: 1969 Double Hump Head Question (Revman)
The 69 Vert I'm working on has a 186 dated 10-21-68 and a 291 head dated June 13,68, with a trim tag date of Dec. 21. Maybe some leftover large valve 291's were used into the 69 models?
The 492 you mentioned was only over the counter? It's not in my black book for Corvettes.
The 492 you mentioned was only over the counter? It's not in my black book for Corvettes.
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Racer
Joined: Dec 2003
Posts: 257
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From: Livermore CA
Re: 1969 Double Hump Head Question (corvgreg)
Greg
My info shows the 291 head as a late 67 and all of 68 head only. In 1969 the heads were redesigned with 3 bolt holes in the front to mount accessories. With a cast date of early June and a built date of later Dec. and with 1 head having the new design and 1 head having the old design, IMO I would say that is the wrong head for your car.
Jeff
My info shows the 291 head as a late 67 and all of 68 head only. In 1969 the heads were redesigned with 3 bolt holes in the front to mount accessories. With a cast date of early June and a built date of later Dec. and with 1 head having the new design and 1 head having the old design, IMO I would say that is the wrong head for your car.
Jeff
Drifting
Joined: Mar 2000
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From: Haysville Ks
Re: 1969 Double Hump Head Question (Revman)
From abook that I have the 3990462 were 1962-to 68, The 3991492 heads were used from 68-73 They were both intermediate and high performance heads. the intermediate had 1.94/150 valves and the high performance were 2.02/1.60. The 3927186 were high performance fro the 302,327 and 350 engine.
