What was the difference between heavy duty cooling and non heavy duty cooling on a `67 GS without A/C? Thanks
It usually was a 4 row radiator in place of a 2 row. That was what I got on a 77 Century when I ordered it "way back when".
Don't know about 67 but in 77 the water pump is the same and the pullys had one less groove. If it didn't have A/C...why would it have A/C components??
my non-AC 67 gs400 came with 4 core rad,no fan shroud,just a small fan guard above the fan, I dont think you would get 2 blocks without overheating if you ran a 2 core rad
It is possible, and I am not a 67 expert, but the more powerful 70 GS 455 cars had only 3 core radiators. Even stage 1 cars with AC in 70 came with 3 core radiators. You had to have a Buick boat (B, C or E body) to get a 4 core radiator in my general experience from looking a quite a few in junk yards. The difference for the HD cooling was radiator tank size the fan in 70 not 4 rather than 3 core radiators. There may have been some other differences in the HD cores.
my guess is the heavy duty cooling came with a fan shroud,a fan shroud makes a bigger diff. than the size of the rad, I have never seen a 67 bb car that did not come with a 4 core rad,small block cars came with 2 or 3 core rads,1970 cars rad support allows a wider(bigger) rad than the 67 support does,so they may have cut back to 3 core in 1970
I had a 70 skylark A body that had the standard 250 cid Chevy 6 cylinder engine. It had a 2 core radiator. It had just a hand guard with no fan cover as I recall. Maybe only a 4 bladed fan but my memory is a little fuzzy about that item.
So the 67 assembly manual verifies a 4 core was correct? Did this vary with the AC option meaning did a non AC 67 GS 400 have a 3 core?
OK ,I dug out my genuine 1967 buick chassis service manual,AC and heavy duty cooling cars are equiped with a 18" fan(400ci)20" fan(430ci) driven by a torque and temp. sensitive clutch,another diff. is the water pump impeller (5 hole AC)(6 hole non AC)there is no mention of fan shroud or rad thickness
George I dont think they used the AC pulleys. The Heavy Duty did have a shroud and the regular had the finger guard.
Has anyone actually seen an original non A/C 67 with a fan shroud that wasnt added later? The 3 non A/C GS cars I parted all had the 4 core rads and finger guard, never a shroud.
Should be able to find the answers in a 1967 Parts book. You have one, right? I thought it included a shroud, clutch fan, and AC water pump. The 1966 AC mod option used pulleys with different pn's than either the standard or AC. I'd guess they are different diameter than the standards, and have less grooves than the AC versions, hence the different pn's. Alan, The AC pulley is smaller than the std, so it drives the pump faster....that's not always a good thing.
