1993 Chevy S-10 Blazer with a 4.3 vortec motor

I have replaced a lot of electric parts on the truck took fuel pressure 59psi replaced tps, iac, tuning valve, map sensor, did a tune up, changed fuel filter, only things I havn't changed is O2sensor and knock sensor.I have replaced EGR valve and I still have this dadblasted surge when cold start at about 1000rpm and when it warms up or gets to operating temp it gets worse it will be so bad the it almost throughs you out of the seat or gives you whip lash! Have also checked the timing base and other wise it is good. Truck also has 207854 miles on it so far I have not done compression check. Ready to pull hair out or start smoking again HELP :