do you have the ego correction turned off? you need to have anything that can influence your tune turned off until you get a good state of tune other wise you will just chase your tale, also check the warm up enrichment isn't adding to much fuel.
if you are using itb's and a big cam you may not be getting a steady manifold signal so you may need to join the itb's with a synchronising hose and maybe put a restriction in the line. alfa/n setting is an option as well altho its a compromise.
is it fuel and spark or fuel only?

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