1993 Chevy K1500 5.7L 350 TBI with 165k miles runs very rough on cold start until warm it smooths out. While driving it's very sluggish/lacks power under load around lower to mid-rpm range.

I've replaced multiple parts including; EGR Valve/Sensor, Fuel Filter, Throttle Position Sensor, Ignition Distributor. I've been told that it most likely needs an intake manifold gasket. Just wondering if I should check anything else before I dive in and what else I should replace if I take off the intake.

 

less replacing , more diagnosing.

the usual stuff, air filter spark plugs. Measure fuel pressure, check for vacuum leaks...

 

Couldn’t find any vacuum leaks when i checked, that’s why i’m thinking it’s intake gaskets, figured when it warms up the metal seats better