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Old Jul 15, 2020 | 11:31 AM
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Question are 78 79 diff covers slightly different than 63 thru 77 covers or are they all the same.
bob
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Old Jul 15, 2020 | 11:52 AM
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They are different. 78-79's use a 7/16" bolt instead of the 9/16" and there is a cast in pad where as the 63-77 have a flat surface.
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Old Jul 16, 2020 | 12:25 AM
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So no problem putting this is in my 76. Yokes have .005 end play drivers side and .019 on passenger side .006 between ring and pinion. Thought I would change seals and put it in. 3.36 ratio along with 200r4 I will be installing. What are your thoughts
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Old Jul 16, 2020 | 12:36 PM
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You have to swap covers that is all. The housings are the same.
78-79's had bad axles, clutches, and RG bolts. The posi case should be checked for cracks. 005 endplay is good 019 isn't as much. If this is a rebuilt diff those are enough of a red flag for me to check it out, others would say use it. 336 isn't the best for an OD trans, 95% of the diff's I built for OD trans were 373's= good 1st gear and cruise RPM isn't too low. Of course the amount of power and torque your engine has will play a big part in it. If it has power and torque then that stock diff should be rethought, if not then the 336 should be rethought.
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Old Jul 16, 2020 | 01:48 PM
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Well crap 383 pushing close to 425hp should I just rebuild my original diff. and change gear ratio it's standard 3.08 now. 1976 vette
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Old Jul 16, 2020 | 06:49 PM
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There is not much difference between 1976 & 1978/9 diff's other then the cover and RG bolts. A properly built one will handle 425 hp unless you are going to launch the car hard. Both are good foundations for building, there was not one perfect vette differential made between 1963-1982, including the 63 Grand Sports, one of which I rebuilt several years ago. Some are much worse then others, your 76 can be built to handle double your power.
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Old Jul 17, 2020 | 01:37 AM
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Gary will this muskegon brake heavy duty cover work on my 76 diff. Also what do you recommend for rebuilding my 76 gears bearings and etc.
bob
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