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**WIDESIDE72** · 02-21-2014, 11:03 PM

Years ago I bought a 8.5" rear axle for my 79 malibu. The axle came out of an early 80's 442. It was 3.73 open the p o had a posi but was scared to install it. It went in with minimal fuss. Btw the way i know the axle was in fact out of a 442 was only the 442 came with 3.73. Posi was optional. Buick GN had 3.42 posi. I understand the 8.5" rear behind the Buick 3.8 turbo, but why behind the 307 Olds but not behind the 305 in the Monte SS?

02-21-2014, 11:03 PM	#10
WIDESIDE72 Senior Member Join Date: Aug 2008 Location: Cedar Park, Texas Posts: 7,500	Re: Factory posi install Years ago I bought a 8.5" rear axle for my 79 malibu. The axle came out of an early 80's 442. It was 3.73 open the p o had a posi but was scared to install it. It went in with minimal fuss. Btw the way i know the axle was in fact out of a 442 was only the 442 came with 3.73. Posi was optional. Buick GN had 3.42 posi. I understand the 8.5" rear behind the Buick 3.8 turbo, but why behind the 307 Olds but not behind the 305 in the Monte SS?