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#72946 02/07/2007 11:23 PM | Joined: Dec 2004 Posts: 322 'Bolter | | 'Bolter Joined: Dec 2004 Posts: 322 | I happen to stop by the garage of the guy who did some of the work on my truck, and he is working on a customers GMC (50?)i/2 ton. He has dropped a 261 in it and he mentioned that the radiator will have to be moved due to the fan hitting it. Is there a short shaft water pump similar to the one on my 235 that will work for this? I always thought that there was a little more room in a GMC than in the AD Chevy and didn't need to be moved. 
Blue 50
1950 3100 w/57 235
Patrick’s Saginaw 4 speed and 3:55 rear end
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#72947 02/08/2007 1:21 AM | Joined: Nov 2005 Posts: 6,100 'Bolter | | 'Bolter Joined: Nov 2005 Posts: 6,100 | Hy Blue 50, the water pumps that are sold for 55 and newer 235s that have a "short" shaft will also fit the 261, hope that helps. I also thought that a G.M.C. radiator was farther forward than a Chevy, maybe it still isn't far enough. | | |
#72948 02/08/2007 5:53 AM | Joined: Oct 2001 Posts: 3,458 Extreme Gabster | | Extreme Gabster Joined: Oct 2001 Posts: 3,458 | The late 261 pump is long enough that it will hit the radiator even on a GMC. The best setup is to use an adaptor plate with the 216 style pump to keep the fan up high so it works. Otherwise you can shorten the water pump shaft but often a mechanical fan doesn't work well. I am running a short shaft pump on mine with an electric fan on the front of the radiator. I have about 1.5" of clearance between the water pump and the radiator but a fan mounted to the shaft would hit the bottom radiator hose.
I'm tearing it out to fit a GMC 302 in there this summer and I expect to have to move the radiator for that, though. I'm going back to a mechanical fan.
Paint & Body Shop moderator
A lone amateur built the Ark. A large group of professionals built the Titanic. | | |
#72949 02/10/2007 1:15 AM | Joined: Jul 2006 Posts: 149 Shop Shark | | Shop Shark Joined: Jul 2006 Posts: 149 | Hummmmm...... Since you plan to rip the 261 out and replace it with a 302 this summer...... what's the possibility of getting your old 261..?
As I'm looking for a good 261 to replace my original 235 dipper motor in my '49.
That is... if you plan on turning the 261 loose...lol
anyway I'd love to chat about it
Michael
509-258-9383
\'48 chev 2-ton boom truck (Boomer) '49 Chev 2-ton flat bed '65 Chev 35ft school bus '88 GMC 6500 '72 Superior 26ft class "A" coach '50 Farmall "M" '71 MGB GT '68 Austin-Healey Sprite '65 Austin-Healey Sprite and various other odd British cars and lots of old radios..... Although we know what the speed of light is..... What I want to know is... How fast is the speed of DARK??
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