The ONLY way to know is to tune via wide band o2 gauge man! Every car is diffrent mine runs twice as good as it did with the stock afb (only reason I didn't tune the stock afb is lack of 3 step metering rods ava now days) I used smaller jets in rear (alot smaller actually) stock jets up front. Metering rod's ended up & 52x71. Also enlarged idle circuit tube .002 end result's are 14.7-15.0 cruise, 12.2-12.0 wot & 12.5 ish idle in gear. It is a very snappy 273. Get a wide band & be very amazed my friend!