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1978 pace car diff. gears

Old Oct 29, 2015 | 01:01 PM
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Default 1978 pace car diff. gears

I have a1978 pace car. L-82, TH350, and I am looking for a project. It has stock diff. gears is there a better choicefor street/strip performance?
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Old Oct 29, 2015 | 01:48 PM
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without knowing what stock is in your case, I would consider a 3:36 or 3:55 depending on how much highway driving you do
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Old Oct 29, 2015 | 03:19 PM
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I have 3.73 gears in mine. A good street/strip compromise assuming you're not driving cross country.
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Old Oct 29, 2015 | 03:35 PM
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Originally Posted by caryb78
I have a1978 pace car. L-82, TH350, and I am looking for a project. It has stock diff. gears is there a better choicefor street/strip performance?

Unless you're planning on drag racing it the stock gear ratio is always the best choice. A set of 3.73's would really wake it up but you'll quickly tire of the high engine rpm when cruising. For a fantastic wake up install a TH700R4 and 3.73's to get the acceleration you want along with a cruising rpm of about 2000 to 2100 rpm at 60 mph.
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Old Oct 30, 2015 | 05:08 AM
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Originally Posted by caryb78
I have a 1978 pace car. L-82, TH350, and I am looking for a project. It has stock diff. gears is there a better choice for street/strip performance?
I suspect your M38 Pace Car was delivered with a 3:08 rearend but here are the codes and options if you wish to check the code.

OK 3.08
OM 3.36
OH 3.55
OJ 3.70

Here's a description of where to look and what to look for:

Codes related to the rear axle ratio are stamped on the edge of the case where it meets up with the cover. Three code sequence configurations were used from 1968-82. Rear axle code numbers are best seen from underneath with the car raised. Late model C3s (1978-82) must have the rear heat shield removed that sits between the rear spring mount and Y pipe.

The codes are stamped on a flat surface, the bottom most portion of the housing next to the plate, which bolts the rear leaf spring to the carrier. The stamp pattern lacks uniformity and in some years stretches across the flat surface. The characters are not necessarily aligned to one another but typically stamped at various angles.
The figure below shows what to look for.




Hope this helps!
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Old Oct 30, 2015 | 11:19 PM
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Originally Posted by BKbroiler
I have 3.73 gears in mine. A good street/strip compromise assuming you're not driving cross country.
No doubt
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