To expand on the above mentioned vortec heads-- those '96 through '99 vortec 350 pick up engines had sequentially fired individual "spider-legged" port fuel injection mounted within a long branched intake manifold, and the vortec heads giving them 255 hp. The '95 350 pickups had the more conventional heads along with a throttle body fuel injection system mounted atop a pretty conventional two bbl looking manifold, they had 190 hosses.
Arguably the bigger feature of the vortec head was the fast burning small heart shaped combustion chambers. Run them babies on your hot rod small block and you had best dramatically reduce your total timing or you'll have to start buying wheelbarrel loads of pistons. Ask the roundy-rounders who didn't.
My '99 3/4 ton Checy pickup pulling the fifth wheel camper will "rattle" up the longer hills in the Texas summertimes even with it's computer and knock sensors on regular gas. Put in some 89 octane and it will get silent and drop a little engine temp doing it, even while running 4.10 gearing with the o/d locked out to protect the 4LE80 tranny.
The higher flow helped the hp, while the fast burn combustion chambers helped the economy (if you can call 9mpg good--but is better than 7, or 8).
hmmm, a stalker mayhaps in yon alley?
