Does rear gear change require PROM update?
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Joined: Feb 2024
Posts: 29
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Car: 91 Z28 / 86 Iroc
Engine: L98 / TPI 305
Transmission: 700r4 / 700r4
Axle/Gears: 3.23 / 2.77?
Does rear gear change require PROM update?
I have a 1991 5.7 tpi and was wondering if changing the 3:23 rear to 3:42 and dont know if this requires a prom update?
Joined: Dec 2004
Posts: 16,774
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From: Mile High Country !!!
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: Does rear gear change require PROM update?
No it doesn’t but you might want to change Vss gears or use a Dakota digital sgi-100 bt to calibrate the speedometer signal. If automatic transmission and gear swap and don’t calibrate the Vss signal tcc lockup will occur at a different speed.
Last edited by Tuned Performance; Today at 08:23 PM.
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