1972 C-10 Longbed, 2 wheel drive, questions - The 1947 - Present Chevrolet & GMC Truck Message Board Network

REEDS 72 · 02-26-2014, 09:59 PM

Okay guys, I have three questions.

What do I do about a bouncing tach needle? From idle to 2000 rpms needle bounces. Seems to smooth out after 2000. I have checked ground wire, power wire and signal wire. All seem to be fine. Does anyone have any suggestions?

I am running an HEI. I am using the power wire from the old coil. I think I have read that it is wrong to use this power lead for the HEI. If so, what do I need to do to get power to the HEI? Could this have any effect on the tach problem above?

How far does the screw in the center of the brake booster, that pushes the piston in the master cylinder, need to be screwed out?

Thanks for any information you can give me.

brad_man_72 · 02-26-2014, 11:47 PM

Id clean the tach 40 years of dust can cause some issues.

You do need a new wire. Just replace the actual wire, the factory wire has built in resistance.

No idea on the master cylinder screw.

Andy4639 · 02-27-2014, 12:34 AM

The orignal wire is a resistant wire and needs to be replaced with just a regular wire so the HEI gets full voltage when cranking the truck. It should also help with that issue also if your having trouble cranking it.
Don't know about the screw.

swamp rat · 02-27-2014, 03:12 AM

I don't want to hijack the thread but can someone say what gauge and resistance the wire should be? Just wanna learn a bit more.

REEDS 72 · 02-28-2014, 08:21 PM

The tach is new the screw in the center of the boster can anyboby give info on that.

ClemsonChevy · 02-28-2014, 11:27 PM

Quote:

Originally Posted by REEDS 72

How far does the screw in the center of the brake booster, that pushes the piston in the master cylinder, need to be screwed out?

Thanks for any information you can give me.

Check these threads:
http://67-72chevytrucks.com/vboard/s...d.php?t=498293

http://67-72chevytrucks.com/vboard/s...d.php?t=601985

And last part of this post
http://67-72chevytrucks.com/vboard/s...62&postcount=8

Maybe this helps a little.

1971 cheburban · 03-01-2014, 09:10 AM

My dad's 69 dodge had the same problem with his tick tock tach dash. But we just drove it easy( I can't lie it's a 440, we didn't drive it easy) but it straightened out after a couple hundred miles. Just drive and enjoy it and wait

jjzepplin · 03-01-2014, 09:44 AM

Or you could just drive it, enjoy it, and wait by the side of the road for a wrecker to come pick you up.

02-26-2014, 09:59 PM	#1
REEDS 72 Registered User Join Date: Apr 2011 Location: AMERICAN FORK, UTAH Posts: 535	1972 C-10 Longbed, 2 wheel drive, questions Okay guys, I have three questions. What do I do about a bouncing tach needle? From idle to 2000 rpms needle bounces. Seems to smooth out after 2000. I have checked ground wire, power wire and signal wire. All seem to be fine. Does anyone have any suggestions? I am running an HEI. I am using the power wire from the old coil. I think I have read that it is wrong to use this power lead for the HEI. If so, what do I need to do to get power to the HEI? Could this have any effect on the tach problem above? How far does the screw in the center of the brake booster, that pushes the piston in the master cylinder, need to be screwed out? Thanks for any information you can give me.

02-26-2014, 11:47 PM	#2
brad_man_72 the boat guy Join Date: Jul 2007 Location: springfield mo Posts: 2,339	Re: 1972 C-10 Longbed, 2 wheel drive, questions Id clean the tach 40 years of dust can cause some issues. You do need a new wire. Just replace the actual wire, the factory wire has built in resistance. No idea on the master cylinder screw. __________________ 67, swb, fleet, tach, throttle, 5.3, 4l60e, 3.73's, fuel cell, 5 lug, p.d.b., 4-6 drop. great little truck 66, stevens drag/ski 18' silouette, 350, 2.02 doublehump heads. comp extreme marine 278 cam, vette 7 fin valve covers, old polished edelbrock intake, velvetdrive, casale v-drive, adj cavitation plate. 28, model a rpu project,

02-27-2014, 12:34 AM	#3
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,936	Re: 1972 C-10 Longbed, 2 wheel drive, questions The orignal wire is a resistant wire and needs to be replaced with just a regular wire so the HEI gets full voltage when cranking the truck. It should also help with that issue also if your having trouble cranking it. Don't know about the screw. __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.

02-27-2014, 03:12 AM	#4
swamp rat Registered User Join Date: Oct 2007 Location: Spanaway Posts: 8,451	Re: 1972 C-10 Longbed, 2 wheel drive, questions I don't want to hijack the thread but can someone say what gauge and resistance the wire should be? Just wanna learn a bit more. __________________ Mike. Swamp Rat build thread : http://67-72chevytrucks.com/vboard/s...d.php?t=595019 72 3/4T 4X4 4" BDS Lift 33" BFG's

02-28-2014, 08:21 PM	#5
REEDS 72 Registered User Join Date: Apr 2011 Location: AMERICAN FORK, UTAH Posts: 535	Re: 1972 C-10 Longbed, 2 wheel drive, questions The tach is new the screw in the center of the boster can anyboby give info on that.

03-01-2014, 09:10 AM	#7
1971 cheburban Registered User Join Date: Jul 2013 Location: Wellsville,ohio Posts: 140	Re: 1972 C-10 Longbed, 2 wheel drive, questions My dad's 69 dodge had the same problem with his tick tock tach dash. But we just drove it easy( I can't lie it's a 440, we didn't drive it easy) but it straightened out after a couple hundred miles. Just drive and enjoy it and wait

03-01-2014, 09:44 AM	#8
jjzepplin Registered User Join Date: Feb 2012 Location: Ruskin Florida Posts: 4,556	Re: 1972 C-10 Longbed, 2 wheel drive, questions Or you could just drive it, enjoy it, and wait by the side of the road for a wrecker to come pick you up. __________________ 70 swb 4x4 406sbc 700r4 203/205 d60/14blt locker yadda yadda http://67-72chevytrucks.com/vboard/s...88#post6935688 Yeller 72 Blazer 2wd conversion project "No Daggum Money" http://67-72chevytrucks.com/vboard/s...d.php?t=550804 LS1-T56 3.73 LSD super budget build Blanco-2014 Sierra SWB https://67-72chevytrucks.com/vboard/...d.php?t=810350



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.