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#1 |
Registered User
Join Date: Nov 2006
Location: OK
Posts: 4
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2 newbie questions
To all seasoned owners,
Sorry in advance for the elementary questions but... I just got my dream, 72 Super, 350, two-tone and I was wondering: 1) what should the RPMs read when traveling at HWY speed (65-75mph)? I have been told about 2500. Does that sound right? 2) If the truck sits outside without starting for a day or two it takes a minute for the engine to turn over for the first time, after that it starts right up. I have been told "350s are just fussy." --not by the seller, I'm not that green. The engine has 22,000 miles on the rebuild and about 55,000 prior to that. Thanks and more silly questions to follow as I find out what I don't know. 72 DCT |
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#2 |
yeeha
Join Date: Sep 2005
Location: Sherwood Park & Fort McMurray, Alberta
Posts: 72
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Re: 2 newbie questions
First off BIG WELCOME from the north and you have come to the right place for help.
As for my help well im still too green to give you a good answer !!! But for my truck i put a fillter in with a little check ball inside to stop the fuel in the carb from running back to the tank. It seem to work for me day to day. But if i let the truck sit for a week well im back to hard starting
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1969 GMC 910 97% rust free 2002 olds Alero 1986 New Yorker 4dr ... the new DD...My POS car... dude its got a turbo!!! Don't drink and drive, you might spill something!!! Daryl Kuchmak |
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#3 |
Registered User
Join Date: Nov 2006
Location: Boring, Oregon
Posts: 162
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Re: 2 newbie questions
1) Rpms all depend on......what trans?? What gear ratio?? What tire size?? My chevy, with a 4spd manual, 3.73s, and 275/60r15s....60 mph(at least that's what my speedo said) was about 3000rpm.
2) Every old chevy i've owned, has done this. After a couple days of sitting, nice long hard crank to start. this happens when the fuel decides to head back to the tank, plus...this also happens when the carburator's float bowl(where the fuel is before it actually enters your engine) gets dry....the fuel evaporates. But.....that choke should help out, feed some fuel back in the system. I like to keep a jumper-pak in the truck with me at all times. Nice when the truck is being stubborn. Another cause of this problem is proper engine timing. too far advance, was my problem.
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'71 SNB, 406sbc, TH350 w/ Transpak & Starshifter, 12bolt w/ 3.73s, 2" Early Classic front coils, 2.5" Flowmaster Super 40's
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#4 |
Woof?
Join Date: Jun 2005
Location: Raleigh, NC
Posts: 276
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Re: 2 newbie questions
Rochester carbs sometimes develop leaks in the fuel wells under the jets. Generally, though, that would lead to hard starting when the truck is warm because too much fuel is getting into the engine. If the leak is minor, after a day or two, it would empty the float bowl and cause the truck to take a bit to start.
You could also check the choke operation when the truck is cold, make sure it closes. In any event, you should have to pump the truck once to the floor to prime the engine and set the choke every time you start it cold. And yes, RPMs depend on rear gears and transmission. I had a '67 C20 with 4.56 factory rear gears, and despite having a new TH-700 in the truck, complete with lockup converter kit, the truck still turned 3k at 50mph. Pushed 5k at 80. That poor 283.
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1968 LWB CST BB 2004 Avalanche Z71 LT3. 2003 S-10 ZR2 (hers). 1997 Astro 1992 Caprice wagon, 500k stock miles. Nursing wounds after a bad wreck. 1997 Saturn - need gas mileage from something! Last edited by Werewolf; 11-17-2006 at 07:13 AM. |
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#5 | |
70+ ( Old Skool Club )
![]() Join Date: Nov 2003
Location: Saskatoon, Saskatchewan ,Canada
Posts: 9,119
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Re: 2 newbie questions
Quote:
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1972 C10 Custom/Deluxe 613 Highlander 406/700R4 1999 White Tahoe LS 4x2 with Z56 Police Package 1992 K1500 GMC Suburban Members I have personally met: MusicMan70 - HeavyD - ChewyChevy67 - StingRay -71SWB4x4 - 67 Burb - DeadheadNM - too much stuff - bc65 - das601 " Circumsatances Do Not Change Responsibility " " The Sky is not the Limit, Your Mind is." Marilyn Monroe .. RIP Charlie Watts 1941 - 2021 |
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#6 |
Designated A-hole!
Join Date: Mar 2003
Location: South Mississippi
Posts: 36,450
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Re: 2 newbie questions
Welcome to the board from South Mississippi!
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"If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. ![]() We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck" |
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#7 |
Registered User
Join Date: Nov 2006
Location: OK
Posts: 4
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Re: 2 newbie questions
Thanks for the quick responses. I'll try to attached some photos next time. The answers to some of your questions that will help answer my RPM question... 3 speed, auto trans, factory tac, tire size 235/75/15. I do not know the rear gear ratio. How do I find it? Thanks again.
Last edited by 72DCT; 11-17-2006 at 03:16 PM. Reason: photos didn't attach |
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#8 |
Registered User
Join Date: Nov 2006
Location: OK
Posts: 4
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Re: 2 newbie questions
here are some photos
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#9 |
70+ ( Old Skool Club )
![]() Join Date: Nov 2003
Location: Saskatoon, Saskatchewan ,Canada
Posts: 9,119
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Re: 2 newbie questions
Nice truck, in fact great looking truck with Cheyenne Package and Factory A/C with the factory tach. Someone will correct me if I'm wrong but I do believe the standard rear end ration for your truck is 3:73 and if its different it will show on the data label on the inside of the glove compartment door. If your ratio is 3:73 you should be turning around 2900 at 60MPH with the 235/75R15 tires.
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1972 C10 Custom/Deluxe 613 Highlander 406/700R4 1999 White Tahoe LS 4x2 with Z56 Police Package 1992 K1500 GMC Suburban Members I have personally met: MusicMan70 - HeavyD - ChewyChevy67 - StingRay -71SWB4x4 - 67 Burb - DeadheadNM - too much stuff - bc65 - das601 " Circumsatances Do Not Change Responsibility " " The Sky is not the Limit, Your Mind is." Marilyn Monroe .. RIP Charlie Watts 1941 - 2021 |
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#10 |
Registered User
Join Date: Nov 2006
Location: OK
Posts: 4
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Re: 2 newbie questions
Thanks. I did more research and you are correct. It is 3:73.
DCT 72 |
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#11 |
its all about the +6 inches
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,693
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Re: 2 newbie questions
actually, it should be 3.07 onless otherwise optioned.
Small block and auto got a 3.07 on 1/2 tons standard. |
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#12 |
Registered User
Join Date: Sep 2006
Location: League City, Texas
Posts: 732
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Re: 2 newbie questions
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#13 |
Senior Member
Join Date: Dec 2003
Location: Colorado
Posts: 351
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Re: 2 newbie questions
Nice truck. Welcome to the board from Colorado.
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The Fastor Pastor '68 swb, 447 BBC/ 6-71 Weiand, Dual 950 Bigs Carbs/ 2 1/2" Header tubes - 4" collectors/ M-21 4speed: '70 swb; TH-400 - bagged & shaved. Looking for new engine or parts. Wife - Original {A Real Classic!} ![]() |
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