To know for certain, you'll need to:
* Consult a repair manual: A factory service manual specific to your 1998 Suburban 350 with the 4.3L V6 will give the precise number.
* Look at the transmission and engine: With the transmission partially removed or visible from underneath, you can count the bolts yourself.
Expect to find somewhere between 6 and 12 bolts. It's less likely to be outside that range. But always refer to a reliable source for the correct information before performing any work on your vehicle.