96 Silverado - Miss at hwy speed

[SoCalSlaughter]

Hello all, I'm finally tired of my truck missing like this, its getting very annoying. Truck is a 1996 C1500 5.7 auto. The truck starts and runs fine. It can cruse around town all day with no problem. But once I get onto the freeway 50mph+ there is a noticeable, intermittent miss at speed. It will cruse smooth for a minute or so then just have a miss and the truck will shudder alittle bit. If I floor it to pass someone the truck is fine, it will fly down the freeway. It seems to happen more at a steady speed. There is no engine lights on, had a full tune up about 8 months ago, fuel pressure is 56/57 psi, MAS is about a year old, crank angle sensor is free and clear of any debris, ignition timing is dead on. The only thing I haven't checked is the fuel injection spider, it still has the old poppet style in there (I know this from doing the intake manifold gaskets about 2 years ago) Thanks in advance