You wrote:
"Thanks for the responses guys. Sometimes a guy just gets worn out <img src="/forums/images/graemlins/wink.gif" alt="" /> That comment from the parts guy also had me pretty bummed. I just wish I could get a couple things fixed that no one seems to know how to fix. That cab leak has me perplexed. I've tried tracking it to up above the fuse box and patching it to no avail. It still comes in during heavy rains."

Last fall I sold my '86. 347K miles. Similar story as yours. Lot's of work to keep it going. I gave up on the original bed and got one straight from Toyota in '99.

As far your leak goes, I had a similar situation and was stumped. I finally decided to dig in. I got under the steering column and pulled out the sound deadening on the firewall and whatever wrapped up and around to the fusebox area. I had a bud run a garden hose directly into the cowl. Water came in at a seam in the upper left hand corner where the firewall bends underneath the A pillar. That seam was liberally coated with seam sealer. I pulled the sealer out and found rust. I took off the cowl and looked in. Where the bottom of the cowl was welded to the firewall, the seam sealer had lifted. In the engine bay, that same seam showed cracked seam sealer, near the clutch master. The fix was clear. Remove the seam sealer, kill the rust, then re-seal it. The downside is that, IMO, this would only be accomplished with the windshield removed. Mine was shot, so I popped it out. From inside the truck I had total access into the cowl area and was able to pick out the sealer, clean the rust out, POR 15 it, and re-seal everything. I used an acid brush to paint on the POR 15, and applied the seam sealer with the finger tip method. It's tight in there! I'd say you must be in a determined mood to deal with it.

Anyway, that seam may be a good place to check. I don't know if it's a common problem. The fix totally cured the leak. A bit painstaking but worth it for me, at the time.