D port vs oval intake

[blackmagic98]

a friend of mine gave me a real nice d port 500 lift cam head he told me to run a oval port intake on it but I do have a d port intake aswell the head and intakes have not been ported or polished has any body run this combination if it was not for him I could not race what a great guy

[Dirtman29]

Using an ovalport intake on a Dport head is usually NOT the way to go, but you can run the opposite. Look at the ports, your fuel flow thru the intake will have to "take a step" up into the head (best way I know how to describe it). I have run it that way before, yes it will run but it will decrease power a bit IMO.