Head spacers is a good idea. But Head spacers will add complexity and possible reliability issues, so I won't use them. Since we are milling the manifold for a custom fit anyways we could have done that I guess. But I think we will be fine with what we have. I want a simple, reliable, low maintinance Engine with some balls so I can run the number at the track. No power adder and nothing too exotic. Sure some of the parts we are using are considered exotic like the pistons and crank and rods, but thats because I want light weight stuff and I want the best quality I can get. The crank had to be a billet just from the fact that there are no forgings that could be used. I have no problem with a forging and I would use that 4.25 callies crank in one of my motors. But with this one I wanted to go BIG! When you open the hood you will see a normal small block in there with big block displacement and TQ. I am not as concerned about rod ratio and Ryan is. Someone just posted about building a 4.25 X 6" rod motor and that is about the same.

Cam clearance in a Mopar Small Block is not an issue.