7.25" to 8.25" driveshaft?

The difference between a 7.25 and 8.25 is about 1.5 ( I think the chart shows 1.25 to be exact ).
If nothing other than the rear was changed that's all you need to know. Take the OEM driveshaft to a shaft shop and have it shortened by 1.5
The extra 1/4 wont hurt anything, just gets the tail shaft seal on new land.