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| | | | Joined: Sep 2007 Posts: 141 'Bolter | | 'Bolter Joined: Sep 2007 Posts: 141 | I have a 261 head which I want to sell. Its casting # is 3836850. I put it on Ebay, and someone asked if it was a standard head or a high compression head. I have tried searching for this info with no luck. Does anyone know how to identify the different 261 heads?
Thanks,
Chris | | | | | Joined: May 2006 Posts: 8,351 'Bolter | | 'Bolter Joined: May 2006 Posts: 8,351 | IIRC, the "high comprssion" 261 head is in reality, a 235 head. I'm wanting to say that was more of a Canadian Pontiac thing, not a truck application.
Bill Burmeister
| | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | Chris,
3836850 is the code for a standard USA truck 261 head (54-62, low compression).
The Canadian Pontiac 261 might have had a high compression head, but the Canadian truck 261 and the USA truck 261 had a lower compression head than was used on a 235.
The person who asked about a "high compression head" on a 261 might have been referring to a high compression "848" (3836848) 235 head (1956-1962) that was/is often adapted for use on a 261 (by drilling 6 additional coolant passages in the head).
Tim | | | | | Joined: Apr 2009 Posts: 431 Shop Shark | | Shop Shark Joined: Apr 2009 Posts: 431 | so that's what the 848 on my head means - high comp? but what does that actually mean in the long run to me and my '61 block? | | | | | Joined: Mar 2005 Posts: 1,513 'Bolter | | 'Bolter Joined: Mar 2005 Posts: 1,513 | Tell the buyer that head 3836850 can be modified to equal the compression of the 3836848 (high compression) head by facing off 3/32".
1952 1300 Canadian 1/2 ton restomod You Tube | | | | | Joined: Dec 2008 Posts: 1,922 'Bolter | | 'Bolter Joined: Dec 2008 Posts: 1,922 | Milling off 3/32" brings the intake valve right down to the piston, removes part of the combustion chamber's original shape, and (if you don't have enough adjustment) requires shorter pushrods. | | |
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