350 studder

[murfs70]

have 70 3/4 ton 4x4 350 has 1000 miles after rebuild,edelbrock cam,edelbrock performer intake,mallory unilte distributor, holley 4150 carb k&n filter. timing set at 14 degrees initial (as per cam) total set at 36 degrees.truck used for desert trips only original problem was pinging,had plenty of power ran great took it to be dyno tuned then problems started hooked up to 32 foot toybox truck fell flat on its face i set timing to where it should be or at least i think where it should be because dyno place had it screwed up, truck runs ok now but not as good as originally, has a studder at high rpm under load and doesnt seem to have the power it had before dyno tune not sure if fuel or ignition. would appreciate any help or suggestions thanks.