Engine Performance problem
1993 Mazda b2200 4 cyl Two Wheel Drive Manual 225k miles
'93 mazda b2200 with carburetor. Engine in truck is a long block with about 30,000 miles. Engine jerks/hesitates after shifting gear and during acceleration at any speed. Engine starts and idles good @ 8,000 rpm. After it warms up runs good for about 1/2 -1 mile then starts acting up. Already had carburetor rebuild thru carb. Shop, replaced fuel pump, fuel filter, air filter, pcv valve and grommet, spark plugs, wires, rotor, cap, and new distrubitor. Also dropped gas tank and checked supply line sock for debris. Disconnected fuel line @ filter and purged with compressed air. Removed valve cover to check cam lobe for wear @ fuel pump lever. Also checked cylinder compression 150 psi all 4 cyl. Check good, and timing is good timing marks lined up on cam and crankshaft with rotor @ #1 on distrubitor. Gutted both catalyc converters and exhaust is good @ muffler. Any suggestions on what to look at next?