I am not one of "those guys that know a lot more" but leave them alone,,they'll be fine. I have run several motors with huge heads and smaller intakes with very good results. You simply have a faster "charge" to the head. I'm sure it's not optimal, but if you match you won't do much other than slow the charge down earlier in it's path to the valve.

Thanks guys. But, I just can't see myself leaving it like this. It just goes against my grain. I am leaning toward leaving the width alone and just raising the top of the intake port to come close to matching the head. I plan on just going in about 1 1/2" into the port to blend.

If the Mfg says not to,why. One thing to think about is if you ever go to a oval port head,you will then have a problem.

I been looking at the pic of your oval ports and how small they look compared to the head port and i know the dyno doesn't lie but what if you had a few individual ports flowed on the intake? If they flow equal or better than your intake ports on the heads,leave them alone and run them.If they flow less than the head ports do than why would you want excellent flowing cnc'd heads that are restricted by the intake,seems like a logical thing to check,Smitty

Those "steps" in the picture? Like they said, they are machining marks from the CNC mill. They use a ball-end cutter and when you step over for the next cut it leaves a little "cusp" or peak sticking up. They could reduce the stepover to a smaller value which would reduce the cusp to darn near nothing. But no need to do this. Intake likes a little texture to keep from wetting the port sides. Exhaust, in my opinion, needs nothing, but the gain you get is minimal unless you go to full polish (and that doesn't stay that way long unless you repolish every three hours or so...).

I thnk I understand the step CStr was talking about where the intake runner leads into the head port. Roby was seeing the "brick wall" as an impediment to flow (which it is). But since it is on the bottom side, where fuel tries to fall out of the stream, the step "launches" the fuel back into the center of the stream where centerline flow rates re-atomize it. Kind of a trade-off: lose a fraction of total flow rate, gain better fuel atomization and burn-ability. At least that's how I see it.

My "eye" hates any mismatches anywhere. But I've watched flow numbers do really weird things with teeny changes that you'd swear would hurt it.

Cooltoys,

In the box with the manifold was a paper from Dart saying that you should match port the manifold if you are using it on a rectangular head. It just seems like alot.

Oh.
It would be a nice trial (although your $22 in gaskets) to do a before and after. Bet you won't see a change. What do you think Mcollinstn?

If you have decided to try to gasket match THAT intake (shown in the picture), then you might as well start over and get the rect port intake.

It's kind of EITHER OR.

Exactly what I was thinking as well. I know it's not an easy choice when trying to make the right selection of components when power is concerned, but why go to all the expense of paying someone to do all that grinding to match them up when you can just buy a rectangle port intake manifold? That's why I was saying that I wouldn't touch a thing and just leave them as they are.

I plan on doing the porting work myself. So cost isn't a factor, time is the only cost. While I don't have a rectangular port manifold here to inspect, I was under the impression that an oval port intake has smaller runners than its' rectangular countepart. That is where the extra power comes from at relatively low rpm's. But, a gasket match should be done just to smooth the transition from intake to head.