Will a 350 bolt to the transmission in 2.8 Chevy s10?

No, a 350 Chevy small-block engine will not directly bolt to a 2.8L Chevy V6 S10 transmission. They have completely different bolt patterns on the engine's bellhousing. You would need an adapter plate to make them compatible, and even then, it's a significant undertaking requiring modifications and custom work. The driveshafts and possibly the rear end gearing would also likely need adjustments.