Ok, first off...are you positive you need to install the drivers?
The pcmcia package that ships with Drake 8.1 covers *a lot* of cards, possibly even the one you have. You didn't mention what card, so I can't even check for ya =/
If you're not sure, try booting up with the pcmcia boot floppy and see if yuo can get your card initialized...if you can...then yer all set =)
I only say this to hopefully save you some hassle.
As to the kernel source...it's not installed by default, but should be available on your Drake CDs (kernel-source-version#.architecture.rpm)