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#69444 12/01/2006 6:22 PM | Joined: Jun 2006 Posts: 74 Wrench Fetcher | | Wrench Fetcher Joined: Jun 2006 Posts: 74 | I have a 56 TF with a 350 motor and 400 tranny. I purchased a 273 posi rear end out of a 78 Trans AM, with the intent to find 308 posi guts to swap out. I'm having difficulty locating the 308 guts. My 56 will be street driven with some highway use, so I'm wondering just how effiecient or ineffiecient the 273 would be given that scenario?
Any input would be welcome. | | |
#69445 12/01/2006 7:37 PM | Joined: Dec 2003 Posts: 2,733 Shop Shark | | Shop Shark Joined: Dec 2003 Posts: 2,733 | About 12+ % fewer RPM's but it might get you out of the torque curve of your engine which you don't describe except as a generic 350. It would help you to know what engine was in the Trans Am. | | |
#69446 12/01/2006 8:30 PM | Joined: Jun 2004 Posts: 8,597 Riding in the Passing Lane | | Riding in the Passing Lane Joined: Jun 2004 Posts: 8,597 | I think it will be just right with normal size tires on it. I run a 70 stepside with 3.08 rear & 700-4r o-drive & it pulls real good. It is a pleasure to drive.
They say money can't buy happiness. It can buy old Chevy trucks though. Same thing. 1972 Chevy c10 Cheyenne SuperIn the Gallery Forum | | |
#69447 12/02/2006 1:19 AM | Joined: Jan 2001 Posts: 613 Member | | Member Joined: Jan 2001 Posts: 613 | a 700r4 has a much lower first gear than a turbo 400. | | |
#69448 12/02/2006 2:10 AM | Joined: Jan 2001 Posts: 687 Shop Shark | | Shop Shark Joined: Jan 2001 Posts: 687 | Originally posted by Wrenchbender Ret.:
I think it will be just right with normal size tires on it. I run a 70 stepside with 3.08 rear & 700-4r o-drive & it pulls real good. It is a pleasure to drive. What kinda revs are you turning in that truck...??? About 800 rpms at 100 mph...?!?!?!  | | |
#69449 12/02/2006 7:51 AM | Joined: Feb 2001 Posts: 1,096 'Bolter | | 'Bolter Joined: Feb 2001 Posts: 1,096 | I have a 2.73 rear in my '73 Monte Carlo , while it keeps the rpm down and allows for very quiet running , the gearing is so tall that the car has little "get up and go" . I've pulled a small caravan with it and it was working hard all the time , regardless of speed.
I think of a truck as being a tool , so it needs to be able to tow a load , carry a load and do it without too much difficulty.
So ......... I think a 350 with a 700r4 and a 3.7 or even a 4.1 rear would be a very handy combo. The overdrive would bring the road gear back close to 3.0.
Great off the line pull and a long leg for the open road. | | |
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