Sputtering under WOT ???

[87Grande.National]

Hey guys just wondering if anyone has experienced this or can help me out on this one, on my 87 GN under WOT it sputters and jerks the car has fresh set of plugs and new vacuum lines, could it be cause by the ignition module and/or coilpack?
Car runs and drives perfectly fine otherwise
And everything on the scanmaster seems to be fine ?

 

[dynoman]

What plugs ??

 

[87Grande.National]

Just the AC delco R43TS but it was doing this before changing the plugs and vacum lines

 

[joed]

O2 volts?
Fuel pump?
Boost?

 

[Chuck Leeper]

Scanmaster readings are?