I finished grinding on the 440 source heads that I'm putting on a customers 383 bracket motor, they have a set of Crane 1.6 ratio ductile iron rockers and 3/8 pushrods. Picture one is of #4 intake port wall, some of them required more grinding than other ones All of the intake rockers required shimmimg away from the stock rocker shaft holdowns My message is make sure your pushrods clear all the way down, at closed and opened

Picture two is of the #2 intake port wall. I didn't think of taking a picture of them before starting, for those that don't have a set yet, sorry. BTW, I didn't have to grind on my Eddy RPM at all with 1.5 rockers and I did have to grind on one intake port wall on another set that has the Harland Sharp 1.6 rockers

Just done the same on mine. Here's a picture before I started.

Just as a warning; the pushrod clearancing limits any porting you may want to in that area.

My heads were CNC ported by MCH so I was worried I would break through the port wall. It's a shame the push rod holes couldn't have been opened up while the heads were at MCH.

After porting the guide clearance is checked, valve spring installed height is checked and shimmed if necessary and he does a multi angle valve job. They should be ready to bolt on, unless you are using 3/8" push rods.

My heads were CNC ported by MCH so I was worried I would break through the port wall. It's a shame the push rod holes couldn't have been opened up while the heads were at MCH.


To clearance push rods I would think MCH would need the block,rocker arms,cam,lifters and push rods. At times there isnt much material to work with.

I had cnc ported stealths put on my motor. It has 1.5 prw rockers on it. I know the builder said they were close with 3/8 push rods, but didnt hit guess I better check them myself.