What flavor is your 486? Does the BIOS support PCI or just EIDE? Whatever the case may be, if you manage to install W98, anybody who uses the system will be miserable just waiting for the mouse cursor to move or for the desktop to refresh after closing a window.
I have a box full of old boards and chips under my desk, waiting for an opportunity to become thin-net clients. The opportunity has yet to present itself.
Consider what you are trying to do: you want to mount a Mopar blower on a lawn mower. Cool idea but that little two-stroke engine won't be able to handle the input.
My suggestion would be to settle for less when dealing with old hardware. Install Win3x or even Win95. They may not offer all of the "enhancements" of Win98 but, at least, they should work.