Clearancing pushrod holes on Stealth heads?

[timinator]

I have a new set of 440 Source Stealth heads. I have plans later of adding 3/8 pushrods and 1.6 roller rockers but I understand there are clearance issues with the size of the pushrod holes. I'm dropping the heads off at a machine shop to have them looked over and thought I might as well have them clearance the pushrod holes now. Anybody have any info/pictures of where and how much metal to remove and the best method for doing this?

[firefighter3931]

I have a new set of 440 Source Stealth heads. I have plans later of adding 3/8 pushrods and 1.6 roller rockers but I understand there are clearance issues with the size of the pushrod holes. I'm dropping the heads off at a machine shop to have them looked over and thought I might as well have them clearance the pushrod holes now. Anybody have any info/pictures of where and how much metal to remove and the best method for doing this?

The best way to clearance for pushrods is to mock up the valvetrain assembly and see where they rub. Generally speaking, the 1.6 rocker ratio will create rubbing issues on the inside of the pushrod tunnel. Unless you are planning on running a roller cam with tons of open spring pressure, you can get by with a thick wall (.080) 5/16 pushrod and still be fine. Saves some headaches and unnecessary grinding. 

If you have to clearance them a die grinder and carbide cutter is your preferred tool. 


Ron

[375instroke]

Well, you need to mock it up to see where it interferes, and by how much.  You can use a high speed steel rotary file on aluminum.  It's much cheaper than carbide.

[mally69]

Hey, I run stealth heads and i use a 1.6 rocker with 5/16 pushrods.  Yes, I did have to use a die grinder to clearance the holes, even with the 5/16 pushrods. Most of the material that I had to take off the head was at the very top and at the bottom of the holes.