I have a 95 mustang gt I put gt40 heads gt40 intake and a b303 cam it’s surging between 800 and 1100 rpm’s the rpm’s hang when I let off the peddle it’s jerks while driving I set the timing at 10 degrees and it’s very sluggish when you take off almost sputtering I don’t know what to do it’s my first build I did use the fuel rail off the donor motor idk if that would cause an issue with the regulator being different there are no vaccum leaks I deleted the egr. Do I have to have a tune? Idk