Truck will bog down while cruising around 60 70mph but otherwise seems ok.

What is your question?

Ok so I'm getting code 33 high signal voltage to map sensor, and code 35 iac problem. Now I replaced iac valve, map sensor, ignition coil, tps, pcv valve, egr valve, throttle body gasket, a few vacuum hoses, and the fuel filter, oh and rebuilt fuel pressure regulator. Seems to run great now except when I hit the highway and around 70 it goes blub blub blub and loses power until u slam the gas then it flies like normal until cruising... Had fuel pump replaces about 75000 ago and truck has 300,000 on it.

What makes this problem better or worse?

cruising at higher speeds makes it worse

How long has your 1995 Chevrolet C1500 had this problem?

About 3 month but got progressively worse