I'm soon planning to rebuild my '71 225 with performance in mind: bored over .100, offenhauser four barrel, performance cam...I am wondering whether the stock 7 1/4 rear will be up to snuff, or should I go for the 8 3/4. My goal for this car is to be a cruiser with some pep. Thanks.

There is also the 8 1/4 mopar rear and the ford 8.8 rear to consider.

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Excuse me, does this smell like chloroform to you?

My friend used to run a 7 1/4 rearend in his 70 Duster. He has a 318, and ran 13s with the rearend with 2.73 gears.

Now he has a 8 1/4 in it.

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1963 Dodge Dart -225 Slant 6, 904, 2.76's, 18.84 @ 73
1970 Nova 12.53@108
1970 Bug 15.38@87

Is the 7 1/4 a sure grip? A 7 1/4 is the weakest of the rears, but not as weak as some would have you believe. If it is a suregrip, it is fairly reliable. I run a 7 1/4 with a 3.91 sure grip in a 13 sec car with slicks. If the rear you have is in good condition, just leave it in. If/when it breaks, then change it.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225