I am buying a smallblock chevy with 68 fuelie heads.I was wondering if I can get by using lead additive instead of spending all the money on updating the valves and whatnot? my dad and myself have a couple flathead engines in some other vehicles that we run lead additive in and havent had a problem. my hotrod truck is a low budget deal less than 4k and runs good but thought I might try the fuelie heads.(cant ever have enough hp ya know)