Mini Spools and Rear Gear Swap

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07-17-2019, 08:26 AM

TimRS

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Join Date: Sep 2000

Location: McDonough, GA

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Car: 91 RS (Sold 90 IROC) 07 Avalanche

Engine: RS 305 TBI

Transmission: RS 700R4

Axle/Gears: 3.42

Mini Spools and Rear Gear Swap

I'm the original owner of a 1991 RS with the original TBI motor. The rear is starting with low whine so I'm considering changing the ring and pinion. It's an automatic car with the original 2.73 gear and I want to go to a 3.73 gear and install a mini spool and obviously a rebuild kit. Has anyone tried this especially in terms of the mini spool. I'm interested in the results and RPM while cruising at 65-70 mph on the highway. Thanks!

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07-17-2019, 09:36 AM

84 z28

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Car: 1984 z28

Engine: 355

Transmission: 700r4

Axle/Gears: Moser 9" 4.11

Re: Mini Spools and Rear Gear Swap

I'd put a locker in it before a spool

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07-17-2019, 11:07 AM

midias

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Car: 1984 Trans Am L69

Engine: Sniper EFI Powered 355

Transmission: WC T5 w/ Steel Support Plate

Axle/Gears: 3.42 10 Bolt Posi

Re: Mini Spools and Rear Gear Swap

I would never put a mini spool on a street car. If you are putting in new gears you might as well get a new POSI. A zexel from a LS1 posi rear will be a good used option. Otherwise eaton or yukon duragrip are popular. Going from 2.73 to 3.73 you are up about 500RPM at the same speed.