About to tune up my 1994 LT1. Replacing plugs, plug wires, distributor, and water pump. Could this design have been more costly? I mean really a distributor behind the water pump, what were they thinking. Any tips tricks or pitfalls for this project?

Well, a silly place for a dist, for sure, but the idea was to get the best timing, with no variances that you get when running the dist off of the cam at a 90* angle...good theory, bad execution. 
It's a time consumer, and you didn't mention replacing the coil/ign module. Now would be the time to do that too, if you hadn't planned on it.

Between the opti placement, fuel filter and battery location, I'm sure the engineers had a good laugh at our expense.  Hope you have a FSM handy.  You might want to spray the hub balancer down with PB Blaster for a few days beforehand, it can be a pain to get off.  And make sure you take pictures for cam pin alignment, so the opti goes back exactly the same way.  And assuming you are going to drain your block, be careful taking the knock sensors out to drain block. And anti-seize on the plug threads (and back of hub balancer) to make it easier to remove down the road. Do your research anywhere you can, lot's of good tips out there for deinstall, install, etc.  jimmymack2009-05-19 09:43:29

Well the tune up is done, the only real snag was the water pump first ac delco one bolt holes were not forged right they were almost triangles instead of circles. 2nd one was fine. Runs like a different car.

 
So...how long did it take ya to do all of it?

Sorry for the long absence, I have had quite a summer with the vette. Apparently after the first tune up which took about 4 days. The distributor went bad and took out the ecm. 2nd "tune up/ distributor" got done at a chevy dealer. Had to order the ecm for them though because the estimated Sept. 19 as the ship date from GM. Got a NOS from Corvette Mike. Since April I have sunk about $5k in 1 tuneup, 2 distributors, an ecm, towing and labor. I'll recoup prolly about a grand in core charges and fighting with the first distributor supplier. Luckily the car was not terribly expensive.

Also afer a summer day driving for about 2 hours straight in rush hour and open road upwards of 75mph how hot should the ecm get? Since I never felt the old one I have no clue, but this this thing is scorching hot.

5K  wow why so much

$2100 to the Chevy dealer who straightened it out. They tagged me for $1100 in labor and almost $800 for the optispark.

The PCM under the hood will get quite hot after a run down the highway...lottsa engine heat to deal with in that position. The insides are fairly well insulated, but the metal parts(outer casing) can get downright nuclear...
Is it running well, now, at least?