porting on heads

[topgunn]

Icanfixall has most or all answers to my questions but any and all advice is much appreciated. I cut a bad head apart to check wall thicknesses. How much material can be removed with-out burning holes in the water chambers? I have two exhaust gaskets,one is stamped steel with 1 and 13/16ths opening. The other (from NAPA) is close to two inches. The head exhaust ports are 1 and 5/8ths. The holes for head bolts are about 3/16ths at one point from side of exhaust port. What is best size opening to go for? Most of the castings have more than 1/4" walls.

I found bushings ( hat shaped) that are used on clevland heads to windsor blocks that should work to use 7.3 heads on my 6.9 block. Any problem using those, they torque to 80 same as ours?

My block is done, so I am working on heads now. Exhaust and turbo mount is next.

 

[icanfixall]

I used the felpro exhaust gasket and thats 1 13/16 diameter. Thats about as far as I feel comfortable going. As you match them up you will find some are way off on placement and size. They are ruffly ground out by the factory. All they are really doing is cutting off the casting flash. Those gaskets that are 2 inch openings souns suspect to me. Would you use them even if you didn't open up the ports??? My exit to the exhaust ports actually are not cut straight into the heads. I actually blended the outside edge of the port to the inner runner. As you look directly down from on top of the head that exhaust port is thin without any water jackets around it. They are around 3/8 inch thick cast iron there. You can make a divider caliper to measure them for thickness. Starret sells a nice one but its really expensive. All you really need is a cheapo chaines made divider for this.

 

[topgunn]

thanks

Thanks for replies.

I thought that I had lost the first post, so I tried again. The stamped set came with the overhaul set, the 2" came from NAPA and are thick paper-like material with metal rings around the ports. I cut up the bad head to check thickness around tunnels. What grit did you use to finish the walls?

 

[icanfixall]

I used a scotchbrite brush. I'll get you the part numbers on them. They actually make a mirror like finish.