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03-21-2013, 08:43 AM
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#1 |
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Registered User
 Join Date: Sep 2012
Location: Factory
Posts: 682
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Oil Pressure at Idle
My oil gauge drops to L when at idle. Then comes up to center of gauge while driving. Dipstick reads full so I haven't worried much.
Just curious where everyone else's gauge reads at idle. Posted via Mobile Device |
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03-21-2013, 09:25 AM
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#2 |
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Account Suspended
Join Date: Feb 2011
Location: Ogilvie Minnesota
Posts: 461
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Re: Oil Pressure at Idle
My 72 is the same way. 350 engine. Not sure on rpm's at idle.
Posted via Mobile Device |
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03-21-2013, 11:20 AM
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#3 |
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Registered User
Join Date: Nov 2009
Location: WEATHEROFRD, TX
Posts: 164
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Re: Oil Pressure at Idle
Mine does the same. If im not mistaken a sb chevy needs 8psi per 1000 rpms minimum. I have never read it anywhere but a buddy told me that has built race engines all his life. Mine when hot idels about 15-20psi
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72 Chevy LB, LS in the works, 4L80, Grandfather bought it brand new. 66 GMC Short Step, 84 Front Suspension, many more mods to come 67 Chevy 3/4 Ton, 327, Auto, Factory A/C Ya must have been movin cause I was haulin a*$ when I passed you |
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03-21-2013, 11:44 AM
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#4 |
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Simple? What's simple?
Join Date: Apr 2007
Location: Southeast CT
Posts: 1,472
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Re: Oil Pressure at Idle
Same, right around 22lbs hot at idle.
What weight of oil are you running?
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CURRENT '50 GMC 100 shortbed Gen IV 4.8 LS - 4L65E (Secret truck, Shhh!!!) Build '63 Buick Wildcat Coupe 401ci Nailhead (Very much in pieces) Photos '66 Impala SS convertible 327-QJet-glide (4 speed swap one of these days...) Photos '69 CST/10 4x4 SWB Stepper 350 2bbl - NV4500/NP241C (Broken Truck!) '72 Sierra Grande 2WD LWB fleetside 350-TH350 Refresh '99 K2500 Silverado RCLB 5.7 Vortec - NV4500/NP241C (Daily) '99 K2500 Suburban 7.4 Vortec - NV4500/NP246 (still working out the bugs) SOLD '71 Custom/10 2WD LWB fleetside - '72 GMC K/3500 Dually (Sold to redryder) |
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03-21-2013, 12:33 PM
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#5 |
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Registered User
Join Date: Sep 2007
Location: Rufus Oregon
Posts: 1,186
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Re: Oil Pressure at Idle
If memory serves me right, small block Chevy's should idle right around 25-30 p.s.i. Weight of oil will effect this. A stock pump put's out this much. I prefer to run a straight 30 weight with these older motors, that's what was recommend back then. Colder temperature run a multiweight oil. I run a high pressure, high volume pump in my '70 El Camino small block 350. It runs around 30-40 p.s.i. at idle, about 50-60 at highway speeds, I've been running this type of pump for years in a lot of my small blocks, dosn't effect them at all.
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03-21-2013, 12:45 PM
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#6 |
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Registered User
Join Date: Jun 2012
Location: Fitchburg,Mass
Posts: 737
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Re: Oil Pressure at Idle
Before pulling my 402 It was around 20-25 lbs at Idle
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62 Willys 4wd Pickup : 72 C-10 swb 504 stroker 09 Taco 3" lift 33" tires: 90 K-5 blazer (plow truck): RIP Ross Little brother
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03-21-2013, 01:28 PM
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#7 |
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406 Powered
Join Date: Aug 2009
Location: waynesville,n.c.
Posts: 877
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Re: Oil Pressure at Idle
10 psi for every 1,000 rpm.
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70 GMC 68 c10 2002 silverado 72 4x4 |
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03-21-2013, 01:34 PM
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#8 |
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Senior Member
Join Date: Jan 2003
Location: daytonabeach
Posts: 22,956
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Re: Oil Pressure at Idle
old hi milage small block chevys it is VERY VERT COMMON to have little to no oil pressure at idle and have the engine run just fine for a few hundred thousand at that point and beyond
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71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY |
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03-21-2013, 01:57 PM
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#9 | |
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Registered User
Join Date: Mar 2013
Location: Willamette valley of Oregon
Posts: 27
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Re: Oil Pressure at Idle
Quote:
 Thats what I've always heard... I have a 72 nova that had a mild 350. The guy I got it from assembled the engine himself. It had 60psi while driving but the only thing that bothered me about it was that the oil pressure would drop to about 10psi at idle after long drives. One day while getting on it going down a freeway on ramp it blew the front main seal. I towed it home & pulled the engine to put in a one piece oil pan gasket. When I pulled the pan I noticed that the oil pump pick-up had been touching it so it was being starved of oil. Every rod & crank bearing was showing copper & the crank was scored. To make a short story long I'm not trying to scare you but this is just something to think about.
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Overkill is an often underrated achievment |
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03-21-2013, 02:24 PM
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#10 |
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1972 K20
Join Date: Apr 2008
Location: Greenfield MN
Posts: 360
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Re: Oil Pressure at Idle
Before my oil change the needle in my stock gauge would be about 1/4 below the first line. I just changed my oil and filter using 10w-30w dino oil (previous oil was the same) and I went from a Fram HP to a Wix filter and now after several heat cycles with the engine at operating temp, my in gear idle (600rpm) oil pressure is a little past (1/4) the first line. I had 918 miles on the oil when I changed it so I dont think it was the oil. I plan on buying Wix filters in the future!
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03-21-2013, 06:01 PM
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#11 | |
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Registered User
Join Date: Jul 2010
Location: MD
Posts: 1,937
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Re: Oil Pressure at Idle
Quote:
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1969 c-10 Step Side Long Bed. I-6 250cid =  = 1969 Pontiac GTO hard top. 400, 4-speed.
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07-07-2013, 02:20 PM
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#12 |
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Registered User
Join Date: Nov 2012
Location: Spartanburg SC
Posts: 87
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Re: Oil Pressure at Idle
Just put oil gauge on. My gauge doesn't read hardly at all until I stop. Do you think something is wrong? I was running it without a gauge connected.
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07-08-2013, 09:49 PM
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#13 |
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Registered User
Join Date: Mar 2011
Location: Sumter SC
Posts: 439
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Re: Oil Pressure at Idle
I just cranked my new motor for the first time and it running 80 at an idle
My build http://67-72chevytrucks.com/vboard/s...d.php?t=468622 Posted via Mobile Device |
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07-09-2013, 02:40 PM
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#14 |
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Registered User
Join Date: Dec 2009
Location: Atlanta, Ga.
Posts: 1,050
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Re: Oil Pressure at Idle
On a hot georgia day after xway driving, mine is 40lbs at speed and 15 at the red light on the exit ramps, touch the gas and back up to 40. thats using 20-50 mobile 1 full syn.
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I don't think we get smarter as we get older. We just run out of Stupid things to do. |
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07-09-2013, 04:12 PM
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#15 |
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Registered User
Join Date: Apr 2013
Location: Knoxville TN
Posts: 1,170
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Re: Oil Pressure at Idle
One way to check idle oil pressure is to remove valve covers and make sure each rocker arm is getting oil. 10 psi per 1000 rpm is a good rule of thumb provided gauge is accurate, oil galleys are clean and clearances are reasonable.
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07-09-2013, 07:32 PM
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#16 |
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Registered User
Join Date: Jul 2013
Location: Campton Kentucky
Posts: 11
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Re: Oil Pressure at Idle
I thought the same thing about mine...it idles about 600 rpm... but at 600 rpm, it only needs 6 psi of oil pressure... given the 10 psi per 1,000 rpm rule of thumb... i changed the oil from 10w-30 to 15w-40 just because i didnt like the low oil pressure, but it didnt change the idle oil pressure any that i could tell(stock gauge) lol
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07-09-2013, 09:39 PM
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#17 |
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Cruzin
Join Date: Dec 2009
Location: on the road
Posts: 2,858
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Re: Oil Pressure at Idle
small block chevy don't need much at idle, if it ain't knocking you have oil pressure
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Lime Wife's 67https://www.google.com/url?sa=t&rct=...wZEMODaS2d94u8 Back to the Fifties 59 https://www.google.com/url?sa=t&rct=...NAeStpydfrcj_U Proverbs 3:5,6 "Thanks to the Interstate Highway System, it is now possible to travel across the country from coast to coast without seeing anything."Charles Kuralt In memory of our first baby daughter, daddy and mommy love you. Danica Grace 6/26/14
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07-09-2013, 10:31 PM
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#18 |
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Registered User
Join Date: Jun 2011
Location: Taylorsville, Georgia
Posts: 482
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Re: Oil Pressure at Idle
Mine sits at 30-45 at idle.
Posted via Mobile Device |
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07-09-2013, 11:51 PM
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#19 |
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Registered User
Join Date: Apr 2013
Location: Flower Mound TX
Posts: 173
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Re: Oil Pressure at Idle
Mine is scary low at full temperature idle. I have an aftermarket set of gauges (reasonably cheap set). It does not knock and gives no audible signs of stress but will get down to lower than 5. Currently running Castroil 10-30 and a Wix filter. Stock gauge is also hooked up and reads about a 1/4 when at idle. I have been slightly worried but knowing it does not take much to keep it lubricated properly. Mine is a SB 350.
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04-09-2025, 04:21 PM
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#20 | |
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Registered User
Join Date: Feb 2011
Location: Modesto, CA
Posts: 2,194
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Re: Oil Pressure at Idle
Quote:
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04-09-2025, 04:21 PM
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#21 | |
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The Older Generation
  
Join Date: Aug 2006
Location: Montezuma, Iowa
Posts: 26,743
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Re: Oil Pressure at Idle
Quote:
Original gauges were 60#. Some bigger trucks had 80#. .
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Leon Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles (My Dually Pickup Project Thread) http://67-72chevytrucks.com/vboard/s...d.php?t=829820 - |
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04-09-2025, 05:52 PM
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#22 | |
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All stock and staying that way
Join Date: Jul 2003
Location: Elkland, PA
Posts: 2,501
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Re: Oil Pressure at Idle
Quote:
Don't trust the OE dash mechanical gauge as gospel. Verify true OP readings with a handheld diagnostic OP gauge.
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1970 K/5 Blazer CST 4WD, TOTM winner December 2024! Medium Bronze poly, 93k ACT. miles, 350, 4 speed, rear positraction, 16.5" x 8.25" HD Kelsey Hayes wheel option, tilt, tach, vacuum, AM/FM, manual throttle...Dad ordered and purchased new 4/70. Frame off restored 1970 K20, To be a clone of my Grandfather's K20, Dark Blue poly, 350, 4 speed, 16.5" X 8.25" Kelsey Hayes wheel option, tilt, tach, vacuum, AM radio. Latest project truck 1972 Cheyenne Super 20 2WD, Dark Blue/White, 90K ACT. miles, 402, TH400, 4.10 open, tilt, tach, vacuum, A/C, AM/FM, manual throttle.. A mostly original paint never rusted Texas survivor...  2017 Sierra 1500 SLT 4WD, Black, 51k miles, 5.3, 6L80E, 3.42 LS, 20" polished wheels, everything but moonroof and 6.2... 2019 Canyon SLT 4WD, White, 71k miles, 3.6, 8L45, 3.23 LS, 18" wheels |
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04-18-2025, 06:40 PM
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#23 |
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Senior Member
Join Date: Feb 2009
Location: Northern Nevada
Posts: 7,692
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Re: Oil Pressure at Idle
I deleted the image and post added earlier, because the image wasn't right. Took it out the other day and observed. When hot, at idle the needle reads a bit more than half way, say 55%. With the accelerator it runs about 75-80%. Seems I've seen it below 50% at hot idle; perhaps so, but 55%-ish is what I'm used to seeing.
My former post read "Old thread...I found it seeking other experiences. Perhaps I can add to it or learn something. Is an original 71 gauge 80 or 100 PSI?"
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Tony 1971 C10 Custom Deluxe SWB 402/400TH A/C I developed an assembly information kit for restoring my truck from nuts and bolts. It's written in Assy. order, short & simple, packed with all OEM hardware ID; castings; part ID; 100s of part numbers; wiring simple - Resource, and trivial too. Much info. applies to all 67-72 GM, A/C vehicles, esp. trucks W/O saying. Full search ability, including to 700+ images of illus., parts, charts, Assy., points of interest, cab, bed, & front clip cart plans- Specials and cores were serviced out and R excluded e.g. front/rear glass, body/paint, engine core, rebuilt hinges, steering box, trans, etc. The project was in-line with long former professions developing process, policy, specs, demo, written for novices, admin., policy, engineers, development, systems & test - Public & govt 2, gross. Sell soft copy cheaply, PM if interested.Build thread:https://67-72chevytrucks.com/vboard/...d.php?t=730025 |
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04-18-2025, 07:35 PM
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#24 |
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Ram-A-Lam-A-Ding-Dong
Join Date: Jan 2013
Location: Simi Valley, CA
Posts: 11,903
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Re: Oil Pressure at Idle
LockDoc posted it up a few replies- 60 PSI; some MD and larger got 80 PSI gauges. Mine pegs the gauge cold, on a 100k mile rebuild, runs near the top under power and ~25 PSI at a hot idle with 10/40 oil. I was thinking rebuild because of oil use, but since I've been putting in synthetic, it doesn't use a drop, between changes.
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~Steven '70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper Simi Valley, CA |
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04-18-2025, 07:51 PM
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#25 | |
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Senior Member
Join Date: Feb 2009
Location: Northern Nevada
Posts: 7,692
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Re: Oil Pressure at Idle
Quote:
__________________
Tony 1971 C10 Custom Deluxe SWB 402/400TH A/C I developed an assembly information kit for restoring my truck from nuts and bolts. It's written in Assy. order, short & simple, packed with all OEM hardware ID; castings; part ID; 100s of part numbers; wiring simple - Resource, and trivial too. Much info. applies to all 67-72 GM, A/C vehicles, esp. trucks W/O saying. Full search ability, including to 700+ images of illus., parts, charts, Assy., points of interest, cab, bed, & front clip cart plans- Specials and cores were serviced out and R excluded e.g. front/rear glass, body/paint, engine core, rebuilt hinges, steering box, trans, etc. The project was in-line with long former professions developing process, policy, specs, demo, written for novices, admin., policy, engineers, development, systems & test - Public & govt 2, gross. Sell soft copy cheaply, PM if interested.Build thread:https://67-72chevytrucks.com/vboard/...d.php?t=730025 |
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