turbodelsolb16a2

b18 ls in a 95 hatch....the timing belt broke....and the head messed up now i got a chance to put vtec....but i don't know because before the car would be realy fast but then recently after 5 rpm...it would lag....so i don't know if it was the head....but what do you guys think i should do to it...go vtec or stay ls....