My truck has the GMC inline 6 and I’m just cleaning up some things in the engine bay. I noticed the coolant hoses don’t look to be in original location (or at least based on what I’ve seen in other photos). Any idea why they would be in this configuration? My engine is first 3 photos… last photo is one I pulled from online.
The hole on the top rear of the head (where your heater supply hose is attached) is used on big trucks to supply flow from the hottest area of the head back to the water pump. Most small truck heads don't even have that hole drilled and tapped. The line on the big trucks was metal, not rubber. That said, this arrangement probably works well and would prevent trapped air at the back of the head.
The valve cover was designed for a PCV equipped truck, not a draft tube equipped engine like yours.
Last edited by Bill Hanlon; 06/06/202512:29 AM.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
... and you really should pitch that Chevy carb. Not even the Chevy guys like them.
Last edited by Bill Hanlon; 06/06/20253:01 AM.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
i'm sorting out hoses also, in the last picture the 2 hoses that come off the water pump to the heater. are they suction on the lower hose and pressure on the top one??
Ther upper hose isn't at the water pump- - - -that's the thermostat housing. It delivers pressurized hot water to the heater core. The lower hose goes into the suction side of the water pump, and is the return line from the heater. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
