Oil Pressure - The 1947 - Present Chevrolet & GMC Truck Message Board Network

narleycarley · 06-11-2010, 07:22 PM

Hey guys, I am putting a big block in my '77 that had a 305 in it. I am having a hard time finding the oil pressure sending unit for some reason. What's up? I believe it's a mechanical guage, not electrical, so... does that mean that i just run the 1/8th inch tubing to the threaded hole, and the guage does all the work? I have an actual oil pressure gauge in dash, not just a dummy light if that helps.

85Bowtie · 06-11-2010, 08:08 PM

Basically, that's all you do. Usually though, a mechanical gauge will come with the fitting for where the old sending unit went. All the gauge does is measure the pressure going to the gauge, hence your oil pressure. Also, you do NOT want to over tighten the fitting where the line goes into the block fitting. It will ruin the ferrel inside and you'll easily get leaks. Also you may want to use some teflon tape on the fitting that goes into your block and at the line connection.

USSkoval · 06-11-2010, 09:27 PM

Quote:

Originally Posted by narleycarley

Hey guys, I am putting a big block in my '77 that had a 305 in it. I am having a hard time finding the oil pressure sending unit for some reason. What's up? I believe it's a mechanical guage, not electrical, so... does that mean that i just run the 1/8th inch tubing to the threaded hole, and the guage does all the work? I have an actual oil pressure gauge in dash, not just a dummy light if that helps.

Yep, the factory tubing threads right into the rear of a SBC. Not sure where it goes on a BBC.

narleycarley · 06-12-2010, 05:49 AM

Thanks ya'll

b454rat · 06-12-2010, 08:45 AM

just above the oil filter.....

68 TT · 06-12-2010, 09:49 AM

Quote:

Originally Posted by b454rat

just above the oil filter.....

And depending upon how old the big block is and if it is a 4-bolt dedicated casting you may need a very large pipe thread adapter to get the oil pressure fitting on it. Some 4-bolt blocks use a 1" pipe fitting for oil cooler outlet that is what you tap into for a gauge. I had to find one of those for my 68.

06-11-2010, 07:22 PM	#1
narleycarley Registered User Join Date: Nov 2008 Location: cove, tx Posts: 69	Oil Pressure Hey guys, I am putting a big block in my '77 that had a 305 in it. I am having a hard time finding the oil pressure sending unit for some reason. What's up? I believe it's a mechanical guage, not electrical, so... does that mean that i just run the 1/8th inch tubing to the threaded hole, and the guage does all the work? I have an actual oil pressure gauge in dash, not just a dummy light if that helps. __________________ '07 Classic '77 C-10 Longbed (under construction) '10 Jeep Unlimited

06-11-2010, 08:08 PM	#2
85Bowtie Registered User Join Date: Mar 2009 Location: TN Posts: 410	Re: Oil Pressure Basically, that's all you do. Usually though, a mechanical gauge will come with the fitting for where the old sending unit went. All the gauge does is measure the pressure going to the gauge, hence your oil pressure. Also, you do NOT want to over tighten the fitting where the line goes into the block fitting. It will ruin the ferrel inside and you'll easily get leaks. Also you may want to use some teflon tape on the fitting that goes into your block and at the line connection. __________________ '69 Dodge Charger R/T 440, 727, 3.55 Sure Grip '68 Plymouth Road Runner 383, 727, 3.23 Sure Grip '89 Dodge Diplomat ex cop car 408, 727, 3.55 Sure Grip '77 Dodge Monaco ex cop car 440, 727, 2.71 '79 Dodge 'Lil Red Express pickup 360, 727, 3.55 Sure Grip '12 Dodge Challenger SRT8 392, M6, 3.92 '85 Chevrolet C-10 SWB 2wd 305, TH350, 2.73 Last edited by 85Bowtie; 06-11-2010 at 08:09 PM.

06-12-2010, 05:49 AM	#4
narleycarley Registered User Join Date: Nov 2008 Location: cove, tx Posts: 69	Re: Oil Pressure Thanks ya'll __________________ '07 Classic '77 C-10 Longbed (under construction) '10 Jeep Unlimited

06-12-2010, 08:45 AM	#5
b454rat Senior Member Join Date: May 2004 Location: Binghamton, NY Posts: 3,454	Re: Oil Pressure just above the oil filter..... __________________ 2000 GMC CCSB 454/4L80 6” lift SAS 1999 Chevy CCSB 454/NV4500 6” lift 1999 GMC Yukon 350/4L60 4" SAS



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