| |
Click on image for the lowdown. 
====
| | | Forums66 Topics128,050 Posts1,055,667 Members48,426 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down
with Ads!  Again, thanks!
| | 
#76907 04/30/2007 9:36 PM | Joined: Oct 2006 Posts: 20 Apprentice | | Apprentice Joined: Oct 2006 Posts: 20 | I have been told a number of times that the 235 head, serial number 848 is a better selection for the 261 engine, because of higher compression. Are there any pitfalls with this match up, anything that I should be aware of. I found a 848 head and I have a 261 block and crank. | | |
#76908 04/30/2007 9:46 PM | Joined: Oct 2001 Posts: 3,458 Extreme Gabster | | Extreme Gabster Joined: Oct 2001 Posts: 3,458 | There are some extra holes in the 261 block between the cylinder bores. These need to be added to the 235 head to allow for proper cooling.
Paint & Body Shop moderator
A lone amateur built the Ark. A large group of professionals built the Titanic. | | |
#76909 05/06/2007 2:01 PM | Joined: Jun 2005 Posts: 887 Shop Shark | | Shop Shark Joined: Jun 2005 Posts: 887 | The 850 head is the 848 for 261s.
If you use a 848 head you'll have to drill the two holes for the steam vents.
'51 Chevy 1/2 ton w/'62 261, HEI, offy, fentons, dual carter/webbers, t-5 & 12 bolt posi
| | |
#76910 05/06/2007 2:23 PM | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | | | |
#76911 05/07/2007 7:20 AM | Joined: Oct 2001 Posts: 3,458 Extreme Gabster | | Extreme Gabster Joined: Oct 2001 Posts: 3,458 | The 850 and 848 head have the same port sizes, combustion chamber shape, and valve size. The 850 just has more meat to lower the compresion on the 261. Don't expect any more flow out of the 848 head, all you are going to get is a smidge more compression, which makes a bit more torque.
Paint & Body Shop moderator
A lone amateur built the Ark. A large group of professionals built the Titanic. | | |
#76912 05/07/2007 9:16 PM | Joined: Dec 2005 Posts: 2,557 'Bolter | | 'Bolter Joined: Dec 2005 Posts: 2,557 | Here is a picture of my 848 head that has had the coolant holes drilled for a 261 block. There are three pairs of holes, hope this helps you out. 848 head coolant holes drilled for a 261 block
1951 3100 Chevrolet1951 Chevrolet Suburban CarryallImage"A house is built with boards and beams. A home is built with love and dreams." "Look deep before you leap !!!" / "Everything is Everything" "If I say a mouse can pull a house, hitch him up"
| | |
|
|
| |
