Hey peoples,

i have purchased a cheap corolla with a 20V 4age motor.
it was once running an entire '97 Ae111 blacktop engine, ecu, and gearbox however the previous owner killed the old blacktop bottom end, and since blacktop engines are hard to find, it was replaced with an ae101 silvertop bottom end.
it still runs the ae111 ecu, with blacktop head obviously. the engine seems run mechanically quite well, although there seems to be an issue with the ignition timing, it seems to not produce any power between 3-5,000 rpm, and hesitates in this rev range.
would the change in compression from the silvertop/blacktop combination affect the factory ignition timing curve on the ae111 ecu?
all other wiring has been double/triple checked, and when advancing the ignition timing it is possible to get the engine to move through that 3-5k rev range easier, however it does ping rather badly.
Has anyone else performed this conversion with this combination of hardware with any success?
any help greatly appreciated ..
thanks,

Chris