I don't see any reason why it couldn't be used... . Hence the reason I included the pic. Reinforcing the firewall shouldn't be any big problem... I'd suggest a piece of sheet metal, say around 12ga or +, and bend it 90* so it can be bolted to the steering column support, the other side flush with the firewall..... That should take care of any support issues... . A piece of angle iron would work well, too, I'd think, say 1/8" thick, 2x4 or so, and then bolt the new mount through it and the firewall. That bracket is included in case the old one is worn excessively or for some reason the current bracket is incorrect..... There were two variations in the '98 trucks, IIRC.
The current bracket mounts just to the inside of the firewall, itself, braced off the steering column support. The bracket pictured above should work perfectly, with a little support of the firewall. I think I included a picture of the factory bracket earlier in this thread... .