I got a 4mil longrod by mistake once,ebay dealer sent me the wrong crank,prolly the only time i have been lucky on ebay. I ran it with 795 pistons and a spacer plate,with my trinity single 35mm,and fmf gnarly pipes with no porting and no problem,but i didnt gain much at all from the stroker without porting. I ran it for a whole season before we tore it back down for porting .
So i can tell you firsthand without porting and the right parts a 4mil isnt worth it.