Water pump studs - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**71CHEVYSHORTBED402** · 03-26-2019, 06:18 PM

Found on the parts book a stud was used to mount the water pump, generally placed on the top passenger side on most trucks. The 70-71 BBC takes two different studs, one is placed on the top driver's side as well.

What were these studs for?

I found mine with 3/8-16 x 1.3/4" bolts. They're stamped with a dog bone, which is era correct, but don't know why I'd have four if it had studs. 1.3/4" seems a little short as well, with a lock washer they're not even using 1/2" of a 1" hole. Not even that with the top alternator bracket mounted by the top driver's side bolt/stud.

http://www.gmpartswiki.com/getpage?pageid=21310

**jocko** · 03-26-2019, 06:34 PM

Tony, I believe they mounted the AIR pump brackets (at first glance I thought one was for the funky bbc alternator bracket, but it mounts elsewhere).

**71CHEVYSHORTBED402** · 03-26-2019, 07:41 PM

No sign of AIR pumps on a 70-71 BBC (Edit: Not quite right. Looks like some variables, Ca. and that) . If the LH top took a stud, which the book says it does, then it did mount the alternator bracket.

You can find the right stud for the RH side (BBC), it's 3759755. Word is the 3/8" thread is 1.75" long.

Lanman1972 · 03-26-2019, 07:50 PM

I don't have my big block at home, but my current project(350) uses one of the studs for the temp sensor wire.

**71CHEVYSHORTBED402** · 03-26-2019, 09:17 PM

Quote:

Originally Posted by Lanman1972

I don't have my big block at home, but my current project(350) uses one of the studs for the temp sensor wire.

3759755, lower LH.

That's the same stud used on the top RH side of a BBC.................................Edit: More specific, a 70-71 BBC takes the 3759755 on the top RH side. And a 71-72 BBC takes the MIA 3927111 on the top LH side. Reads it's a 3" stud end to end.

71 was sure on the cusp of things. Part 70, part 72. If it's my Chevy then it's part 70, part 72 and part GMC considering the leaf springs

I mean

**71CHEVYSHORTBED402** · 03-27-2019, 09:37 PM

BBC water pump studs anyone? Curious what the LH stud looks like, and what each one was used for.

**71CHEVYSHORTBED402** · 03-27-2019, 10:39 PM

Quote:

Originally Posted by jocko

Tony, I believe they mounted the AIR pump brackets (at first glance I thought one was for the funky bbc alternator bracket, but it mounts elsewhere).

Check it out Jocko: https://www.zip-corvette.com/66-82-a...pump-stud.html

I think it's the stud I'm looking for (3927111), though the short end seems long. Then again I don't know what its used for yet

. Definately not the temp sensor like Lan's 72, because they're on the RH head for a BBC. That's my understanding anyway.

**Longhorn 69** · 03-27-2019, 10:58 PM

Tony, the LH, Passenger side stud is fine threads, I think it must be for the A/C compressor, but not sure. The RH Drivers side stud is for the lower bolt on the Alternator bracket and is course thread. Thats the way my 396 is set up.

**Longhorn 69** · 03-27-2019, 11:01 PM

trying to attach pic.

**71CHEVYSHORTBED402** · 03-28-2019, 12:29 AM

Quote:

Originally Posted by Longhorn 69

Tony, the LH, Passenger side stud is fine threads, I think it must be for the A/C compressor, but not sure. The RH Drivers side stud is for the lower bolt on the Alternator bracket and is course thread. Thats the way my 396 is set up.

Sorry, it's confusing, by RH I mean passenger side. Th passenger side stud isn't for A/C, though it might be for a retainer of some sort. Agree, the LH (driver's side) stud mounts the alt. bracket. But being it's a stud, seems to imply it secures something else as well.

Quote:

Originally Posted by Longhorn 69

trying to attach pic.

Nice long horn, thanks.

OT.........I found my water pump and thermostat with lock washers. Correct me if I'm wrong, but I don't think they're suppose to use lock washers.

Was shopping for "correct" (marked "TR") and replacement bolts for the thermostat housing. All of the "correct" bolts measure 1" and 1.7/8". Strikes me odd considering even without a lock washer and gasket, the long bolt grabs nothing but 1/4", while the 1" takes 5/8"............Came up empty for a 2" "TR" bolt. ARP black oxide will work, they come 1" and 2". On a side I think some applications took a stud(s) instead. Read a post by an antique owner who swears by studs. Seal and install for permanent to avoid stripped cast iron threads

03-26-2019, 06:18 PM	#1
71CHEVYSHORTBED402 Senior Member Join Date: Feb 2009 Location: Northern Nevada Posts: 7,292	Water pump studs Found on the parts book a stud was used to mount the water pump, generally placed on the top passenger side on most trucks. The 70-71 BBC takes two different studs, one is placed on the top driver's side as well. What were these studs for? I found mine with 3/8-16 x 1.3/4" bolts. They're stamped with a dog bone, which is era correct, but don't know why I'd have four if it had studs. 1.3/4" seems a little short as well, with a lock washer they're not even using 1/2" of a 1" hole. Not even that with the top alternator bracket mounted by the top driver's side bolt/stud. http://www.gmpartswiki.com/getpage?pageid=21310 __________________ Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assembly kit for restoring the (a) truck from the ground up. My build thread, and more on the assembly kit https://67-72chevytrucks.com/vboard/...d.php?t=730025

03-26-2019, 06:34 PM	#2
jocko Senior Member Join Date: Oct 2009 Location: Godley, TX Posts: 17,976	Re: Water pump studs Tony, I believe they mounted the AIR pump brackets (at first glance I thought one was for the funky bbc alternator bracket, but it mounts elsewhere). Attached Images

03-26-2019, 07:41 PM	#3
71CHEVYSHORTBED402 Senior Member Join Date: Feb 2009 Location: Northern Nevada Posts: 7,292	Re: Water pump studs No sign of AIR pumps on a 70-71 BBC (Edit: Not quite right. Looks like some variables, Ca. and that) . If the LH top took a stud, which the book says it does, then it did mount the alternator bracket. You can find the right stud for the RH side (BBC), it's 3759755. Word is the 3/8" thread is 1.75" long. __________________ Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assembly kit for restoring the (a) truck from the ground up. My build thread, and more on the assembly kit https://67-72chevytrucks.com/vboard/...d.php?t=730025 Last edited by 71CHEVYSHORTBED402; 03-28-2019 at 12:38 AM.

03-26-2019, 07:50 PM	#4
Lanman1972 Registered User Join Date: Dec 2013 Location: Omaha NE Posts: 620	Re: Water pump studs I don't have my big block at home, but my current project(350) uses one of the studs for the temp sensor wire. Attached Images __________________ 1972 C10 Custom Deluxe LWB, 402/400, PS, PB, A/C, Highlander, Hugger / White 1971 C10 Cheyenne LWB (SWB), 350/350, PS, PB, A/C, Dark Olive / White.

03-27-2019, 09:37 PM	#6
71CHEVYSHORTBED402 Senior Member Join Date: Feb 2009 Location: Northern Nevada Posts: 7,292	Re: Water pump studs BBC water pump studs anyone? Curious what the LH stud looks like, and what each one was used for. __________________ Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assembly kit for restoring the (a) truck from the ground up. My build thread, and more on the assembly kit https://67-72chevytrucks.com/vboard/...d.php?t=730025

03-27-2019, 10:58 PM	#8
Longhorn 69 Junior Member Join Date: Oct 2017 Location: Oregon, Ill. Posts: 62	Re: Water pump studs Tony, the LH, Passenger side stud is fine threads, I think it must be for the A/C compressor, but not sure. The RH Drivers side stud is for the lower bolt on the Alternator bracket and is course thread. Thats the way my 396 is set up. __________________ Greg 69 Longhorn 396, 4 Speed SM 465, PS, PB, No Air

03-27-2019, 11:01 PM	#9
Longhorn 69 Junior Member Join Date: Oct 2017 Location: Oregon, Ill. Posts: 62	Re: Water pump studs trying to attach pic. Attached Images __________________ Greg 69 Longhorn 396, 4 Speed SM 465, PS, PB, No Air



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