360 head mild port question

You can open the 318 to the 360 gasket. Stock style gasket but you have to taper the roof because it's not as high. I did it on my thread... 318 head porting for the average joe. The gain is about zero without a lot of port work , gained 4 cfm after a full port job w/1.78 valve. Dont get carried away on the exhaust. .it will easily outrun the intake port

Just blend the farside bowl, just off the lower 60 angle to the turn...lay the top of the turn back evenly across and work the straight/siamese wall between the guide for width. A nice straight shot to the cylinder wall on that side what your after on them.
Hard to **** those heads up.