on a 1995 chevy 3500 with a 454 was there some sort of intake tube that connected the airclean to the passenger fender? kinda seems weird that the airclean would just suck in hot air from passenger exhaust manifold. any have pics or has anyone built a tube to connect the 2?

This is a 5.7 but you'd see essentially the same setup on all TBI engines:



The path of air starts at the bottom passenger side of core support, that "scoop" sort of behind the park light. Goes into the interior of the passenger fender. Comes out through that round outlet and into the silencer box, then flex snorkel, into your air cleaner housing, through the heat riser flap, filter, and finally into your TBI.

I deleted my silencer box and used the flex tube from a base model V6 that came without a silencer.



I also chopped the heat riser flap and its wax pellet assembly out and patched up the holes, including the round part at the bottom for the heat riser tube from the exhaust manifold. I later replaced this with a lower housing from a '95 3/4 ton that didn't have a heat riser at all from the factory:



The factory setup is sort of like OEM "cold air induction" - not really airtight or anything, but WAY better than sucking in hot engine compartment air, and gets better with a few small improvements like I mentioned.

Also, on 88-92/maybe 93 GMT400's there is a piece of ductwork inside the fender that can come out. GM quit using them after those years.

Richard