Good video. Thanks.
I was tempted to do it, but I ran into a dynamics wall with my build and figured that any gains I would have made with my 318 build in flow, I would have lost equally, by increasing port volume and dropping velocity, from the jump in port size at the gasket area.
I'd love to keep the 318 port size and make the transition nice and clean, but it only helps if your intake runners are really squared on the engine, by moving the intake manifold forward/backward, and not just the same shape as the gasket. Otherwise, you could have exact port shapes, coupled with completely incorrect alignment.
The gasket will index on the head with the metal or plastic index tabs, or the bolts like he did, but in order for the intake to mate perfectly with the head and gasket, it's not just a matter of placing the gasket on it and doing the same thing.
Even newer intakes suffer from core shift to some degree. You have to check for runner pair spacing differences (the distance between [1][3]<--distance measured-->[5][7] ), up/down shift/ staggered differences, within each paired runner and centering differences in the thin divider walls, between the paired runners, on the left and right cylinder bank, when the heads are installed and intake in place.
The intake centering dowels should be taken out of the block at the front and rear, to do the centering.
You scribe or mark the intake runner thin divider walls down the center and continue a visible mark on the top of the runner pairing, to see when the intake is in place.
Then, you do the same with the head. Mark the center of the skinny divider wall and continue the mark up the cylinder head, so you can see it with the intake in place.
You do this on all four runner pairings of the intake and on the heads, then you set the intake on the engine and locate the marks on one bank. Look at the opposing cylinder bank. The difference between it's center marks half of how much the manifold will need to move, to compensate both sides.
Then, you mark the intake silhouette against the gasket, or use witness marks against both( I do both) once it's been corrected/ centered and pull the intake off.
Set the gasket back on the intake with your witness marks in place and look at the gasket against the intake runners. Whatever you see of the intake is what will need to be blended, at least an inch or two up into the runnner for a smooth transition.
The one thing everyone should do is deburr the runners. The blob in the runner on the video is unsightly enormous. I've never seen anything like that, but I've seen other imperfections. Anything you can do to make the runners look and feel the same, the better it will respond in throttle and show even power.
If you want real gains, center the intake before placing the intake gasket on and cutting the ports on it, after you've gasket matched the head, or don't bother with the port matching.
