Thinking of Updating to this 427 CUI

[Aussie Mike]

I think one of the issues with the 347 is the short rod length making for a poor stroke to rod length ratio. There are a few kits available now with different rod and piston combinations.

I think 5.31" and 5.4" rod lengths are the main options. The longer rod giving the better stoke to rod lenght ration and rod angle. The down side is that the longer rod puts the piston pin in the oil ring land so can affect oil control.

I think this is why the 331 was more popular as it ran a slightly shorter stroke and resulted in a better rod angle.

There are now more pistons available with better materials and designs including things like offset pins to control the extra side thrust from the short rod angle.

The other thing that has helped is the advent of stonger after market blocks. The stock bottom end can suffer with the extra loads (Ask Waz). My Tickfor motor uses the stock block but they added a main bearing girdle and also set the rev limiter at a more conservative 5850 RPM.

Cheers