I have a problem with my 1990 5.0 if anyone can input that’ll be dope. I have a current lean condition. I have a 306 w/ gt40 heads and intake .stock valves from a stock 5.0 heads. B303 cam. Stock exhaust with cats. It has no smog pump nor egr . At idle I have full lean (20+ on my afr gauge) but when I give it gas it goes down to 14 Ish. I’ve done a tps reset base timing @10 degrees btdc. I I have New tps iac spark plugs fuel injectors, fuel pump, good oil/fuel pressure , bottom end was fully rebuilt. Couldn’t find any vacuum leaks. Any ideas?