'67 12 bolt gear ratio - The 1947 - Present Chevrolet & GMC Truck Message Board Network

TCLARK · Today, 12:28 PM

I have a '67 Chevy SWB frame with a 12 bolt....trying to figure the ratio, best I can tell it comes out to be a 340. I don't know if it's really a 336,342 or 355. Guess I'll have to pull the cover off. I think it was an I6.

**Palf70Step** · Today, 01:23 PM

If your count is correct it is probably a 3.42. I have not heard of a 3.55 or 3.36 used on GM trucks.

**'68OrangeSunshine** · Today, 02:36 PM

Quote:

Originally Posted by TCLARK

I have a '67 Chevy SWB frame with a 12 bolt....trying to figure the ratio, best I can tell it comes out to be a 340. I don't know if it's really a 336,342 or 355. Guess I'll have to pull the cover off. I think it was an I6.

My truck ['68 C/10 Stepside] came with a Factory 292 L6 and a 3.73 rear end ratio.

Today, 12:28 PM	#1
TCLARK Registered User Join Date: Jun 2009 Location: COOKEVILLE,TN Posts: 145	'67 12 bolt gear ratio I have a '67 Chevy SWB frame with a 12 bolt....trying to figure the ratio, best I can tell it comes out to be a 340. I don't know if it's really a 336,342 or 355. Guess I'll have to pull the cover off. I think it was an I6.

Today, 01:23 PM	#2
Palf70Step State of Confusion! Join Date: Jul 2002 Location: Gulfport, MS USA Posts: 46,894	Re: '67 12 bolt gear ratio If your count is correct it is probably a 3.42. I have not heard of a 3.55 or 3.36 used on GM trucks. __________________ Bill 1970 Chevy Custom/10 LWB Fleetside 2010 Toyota Tacoma PreRunner SR5 Double Cab - DD Member of Louisiana Classic Truck Club (LCTC) Bill's Gallery Life isn't tied with a bow, but it's still a gift. Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God!



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