Motive R&P - Third Generation F-Body Message Boards

87ROCZ · 09-15-2009, 08:02 PM

Hi,

I am looking to replace my B&W 3.27 posi rear gears to a set of 3.70 ratio gear from Motive Gear.

I looked at Motive catalog and they sell one gear set 3.70 for our 9 bolt (7.75" rears)... Will this be a direct fit for my 1987, G92 optioned, 3.27 BW posi, rear end or will I have issues with the carrier (I know that there are differences between carriers, ie: 3 series, 2 series, etc etc)

Here are the specs...

Application: 1985-1993 GM 7.75 Australian BW 9 bolt (Camaro, Firebird, Trans Am)
Carrier: 3.07 and numerically higher (3.07, 3.36, 3.55, 3.73, 4.10, etc.)
Ratio: 3.70
RG diameter 7.75"
Pinion diameter 1.376" 27 spines
Part number: GM9-370
Warranty: 1 year (manufacturing defects)

Any help would be appreciated before I buy this R&P and their Master rebuild kit...

TIA!

big gear head · 09-15-2009, 10:08 PM

The 3.27 and 3.70 both use the 3 series differential. You should be good.

87ROCZ · 09-15-2009, 10:49 PM

Thanks gear head... I needed to make sure that they both use the same carrier before I bought them, wouldn't want to get them, go to install them and have a "Ahh crap" moment

.... what threw me off was the statement

Carrier: 3.07 and numerically higher (3.07, 3.36, 3.55, 3.73, 4.10, etc.)

I never saw my 3.27 ratio in that list so I wasn't sure....

Slow89Iroc-Z · 09-16-2009, 12:17 AM

I am trying to install these right now and am having a hell of a time....

87ROCZ · 09-16-2009, 02:13 AM

really ..why is that? I won't be installing the gears... I will be giving it to a local speed shop that set up my buddies GTA with a set of Yukon 3.73's for his 9 bolt.. so they know what they are doing when it comes to rear diffs...

Just wondering what issues you are having, maybe it's specific to these Motive gears?