96 Blazer 4x4, 116,000. While attemping to replace the thermostat, I snapped the front bolt below the thermostat cover. The bolt nearest the carb came out of the block. Neither of the nuts on top of the cover moved. I'm curious as to why there is a bolt going into the block and a smaller one coming up and through the cover with a nut on top. Why not just put a bolt going down and through the cover? I used an "easy out" and got the bolt out fairly easily. I then replaced it with a simple bolt of the same length.

Jim

 

I don't have an informed, definitive answer to your question. My best guess, however, is that the engineers who designed the engine were mostly concerned with speed and cost of assembly. Long threaded studs make assembly quicker and cheaper.