Can a gm 8.8 bolt 3.73 gears fit in a 10 bolt?

No, GM 8.8-inch bolt 3.73 gears cannot fit in a 10-bolt rear end. The 8.8 and 10-bolt rear ends have different gear designs, sizes, and configurations, making them incompatible. If you're looking to change gears in a 10-bolt rear end, you'll need to use gears specifically designed for that axle.