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| | | | Joined: Jul 2007 Posts: 41 New Guy | | New Guy Joined: Jul 2007 Posts: 41 | What would be the possible ratio options? One? More than one? 3.73? | | | | | Joined: Jul 2006 Posts: 707 Shop Shark | | Shop Shark Joined: Jul 2006 Posts: 707 | 3.73 sounds credible. Could also be 4.10.
1951 3800 Be the change you want to see. -hotshoe
| | | | | Joined: Apr 2003 Posts: 942 'Bolter | | 'Bolter Joined: Apr 2003 Posts: 942 | If the truck can go about 60 before it sounds like it's revving too much, it's probably a 3.73.
To find out for sure, besides taking off the rear cover, you could raise the truck, spin the wheels and count the driveshaft turns (altho a non-posi procedure works different), and there also should be a code stamped on the rear you could decipher.
Bill
'60-'72 Chev/GMC Fan
GMC 9500 Fan
Detroit Diesel Fan
| | | | | Joined: Jun 2005 Posts: 1,756 Shop Shark | | Shop Shark Joined: Jun 2005 Posts: 1,756 | Non posi, I believe you double your result.unless you turn both wheels at the same time.
Last edited by gazim; 11/10/2007 3:44 PM.
| | | | | Joined: Apr 2003 Posts: 942 'Bolter | | 'Bolter Joined: Apr 2003 Posts: 942 | Right, that's the way I have learned it and since have heard others verify it, when turning one wheel anyway. Double what you get.
Bill
'60-'72 Chev/GMC Fan
GMC 9500 Fan
Detroit Diesel Fan
| | | | | Joined: Dec 2002 Posts: 3,445 Moderator - The Electrical Bay | | Moderator - The Electrical Bay Joined: Dec 2002 Posts: 3,445 | my 66 GMC was ordered with a 3:73 posi
Another quality post.
Real Trucks Rattle
HELP! The Paranoids are after me!
| | | | | Joined: Mar 2006 Posts: 319 Shop Shark | | Shop Shark Joined: Mar 2006 Posts: 319 | I believe our site sponsor provides some info about ratios for this year under axle codes. http://www.americanclassic.com/paint.htm?p1=axlesI inquired about a 12 bolt rear end for sale recently and was told there was a sequence of HQ 1215 W on the axle. I interpreted this as a 1966 3.73 ratio built on December 15 at Warren, MI if I recall correctly. Another vendor provides a list of RPO codes for rear ends on their site. The RPO numbers may be found on a sticker in your glove box? http://www.drivetrain.com/gm8.875trk.htmlhttp://www.drivetrain.com/GMtrkratio_posidata.htmlHope this helps.
Last edited by randy luton; 11/10/2007 7:57 PM.
"Nothing astonishes men so much as common sense and plain dealing." - Ralph Waldo Emerson
| | | | | Joined: Mar 2004 Posts: 3,068 'Bolter | | 'Bolter Joined: Mar 2004 Posts: 3,068 | The available choices that year were a 4:11, 3:73 or a 3:07 in the 1/2 ton truck,
Scott | | | | | Joined: Jul 2007 Posts: 41 New Guy | | New Guy Joined: Jul 2007 Posts: 41 | Thanks for all the great info!!!!!!!!!1
It does feel pretty comfortable at 60 but I don't like to take it over 65. I've put taller tires on the rear to help a little. | | |
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