Please elaborate 'cannot get an IRQ'??
Assuming that these are PCI or embedded network and video controllers, do they appear in Bios?
If they do, then Win98 should auto-detect them and load, or attempt to load, the correct drivers.
Things should work if shared interrupts are used, but you may need to do some fiddling in Bios if shared interrupts are a problem.
In some cases you can disable a motherboard device you are not using in Bios setup. Then find the slot that shares its interrupt with this (now diabled) device and place your adapter in it. Even though it is still sharing its interrupt with the motherboard device, it will not be a problem since the device is turned off.