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davepl · 03-21-2018, 12:31 PM

Definitely keep the 3.73s... if you had 3.08s, we'd be telling you to swap for 3.73s anyway!

I'm restoring a '69 2+2 and while it has 3.31s because it's a manual, I saw that the default axle for the LS1 427 (335hp) with the TH400 was the 2.56 rear end. That's a steep setup! But 3.08s with OD would be significantly steeper than that even.

Assuming a .7 OD you'll wind up at 2.61:1 which is darned close to that 2.56:1 number!

03-21-2018, 12:31 PM	#15
davepl Registered User Join Date: Aug 2006 Location: Redmond, WA Posts: 6,332	Re: 3:07 Rear End Definitely keep the 3.73s... if you had 3.08s, we'd be telling you to swap for 3.73s anyway! I'm restoring a '69 2+2 and while it has 3.31s because it's a manual, I saw that the default axle for the LS1 427 (335hp) with the TH400 was the 2.56 rear end. That's a steep setup! But 3.08s with OD would be significantly steeper than that even. Assuming a .7 OD you'll wind up at 2.61:1 which is darned close to that 2.56:1 number! __________________ 1970 GMC Sierra Grande Custom Camper - Built, not Bought 1969 Pontiac 2+2 427/390 4-speed Coupe 1969 Pontiac 2+2 427/390 4-speed Convertible