| Porting your iron pass car heads pictorial |
| pg. 1 |
| Step 1 Become familiar with port wall distance to water.! The areas to the right of the guide and to the right of the thermact-air boss (port roof/long side) are the danger areas. There is water over right side port roof, until you near the thermact-air bump near the port exit. There is water between the exh. bowl and intake bowl |
| Minimun port wall thickness: .100 to .125" Street duty. ..080" strip only. You are asking for cracking if you overheat the casting. |
| Large area shown to the right is the thinnest area. You can not lay back the right side roof to the same height as the left side roof. |
| This port design was large, and in retrospect has many errors. It was one of the first ports I did for this guide. the upper right hand corner is too squared off. The outlet size is even larger than the felpro 90291 exh. gasket.I used as a guide. Although the port can be made wider finding headers becomes an issue.Wider will cause cause port to header flange mismatch issues |
| After beginning to poke and prod with an awl, the awl went thruogh the large hole on the right side roof like a knife through butter |
| Compromise is necessary with regard to port roof height, right side. Approximately 1/16" or .0625" is about minimum it should be lower than left in comparison. |
| 429/460 |
| Further research on the bench has shown that when shaping the right and left trenches on either side of the valve guide boss for max flow, there is no danger of hitting water if you are conservative and follow the pics and measurements closely and carefully. Raising this area past a certain point doesn't help flow any further. 12-02 |