Switching differentials
Thread Starter
Melting Slicks
Joined: Sep 2006
Posts: 2,812
Likes: 469
From: Wichita Kansas
Switching differentials
Does anyone know if a 2.7XX exists that will switch out with a '72 rearend without modification, and where I would go to look for one? it's a stock 350 auto. Thanks.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
3.08 is readily available. A lot of guys dump these for a 3.70 for better performance. Just curious, why a 2.70? with a stock 350 auto it will be a real dog and won't improve gas mileage.
Tech Contributor
Joined: Aug 1999
Posts: 15,166
Likes: 3,968
From: Connecticut, USA
You can buy a 273 gear to fit your 72 posi case. The other ratio's are 308 336 355 370 373 390 411 433 456 all made to fit a 3 series case.
I built a 273 for my buddy. He put it in his 76 stockL48, 4 spd car and likes it. The ST-10 has a 2.64 1st gear.
I built a 273 for my buddy. He put it in his 76 stockL48, 4 spd car and likes it. The ST-10 has a 2.64 1st gear.
Thread Starter
Melting Slicks
Joined: Sep 2006
Posts: 2,812
Likes: 469
From: Wichita Kansas
Gas mileage improvement was a goal, am surprised the change would not help. The Vette gets up and goes p-d-f but that's not necessarily a plus for us. Just raps the rpms way up there at 70 and away goes the gogo juice. I am not sure what I have right now, something tells me it's a 3.55; if it is a 3.08 I will not mess with it. I have the codes so will look on the bottom of the dif and see what it is. Thanks for all the responses.
