Looking for advice on basic engine mods to boost performance.

[eran tomer]

Heat riser? My '88 had no heat riser valve. The TBI manifold has a big coolant passage that warms the manifold.

Or are you talking about the temp-sensitive door in the air cleaner snorkel? GM used to use a vacuum-operated system, but the GMT400s seem to get a wax-pellet, self-contained door and thermostat.

i have seen an air cleaner that doesn't have it. it's from an over 8500 lb emission car. does it make sense?