Predator 420cc HEMI Build Help

[@gokartgod]

Looking for some advice here. Have experience with 212's but no experience with the hemi 420's.



Currently, the engine is stock except for the stage one kit to hold the place for the Mikuni 34mm and custom exhaust.



Looking for top end performance.



The only part I currently have is a billet flywheel with timing adjustment.



Need to do some porting and polishing at the end of all of this.



Want to install

-Billet rod

-Mod 1 or .308 Cam

-Chromoly push rods

- 65lb dual Springs

-Mikuni 34mm



1: Will the stock spring retainers and keepers work for the dual springs? If not what do you recommend?



2: Is 65lb springs the best option for my build or should I use 50lb springs?



3: 308 Grind Cam or Mod1 Grind Cam? Will I need to clearance the piston to clear the valves?



4: 4.410 or 4.450 Billet rod? Will I run into clearance issues running the 4.450 rod?



5: Mikuni 34mm Round Vs Flat?



6: Is there anything I am missing or anything you would recommend I change?

[raydhd]

You probably going to need the NR billet rocker arms for that much camshaft. You might want to look at Shepard's Magnum build page #8 item #76 for an explanation of the problem which I just bumped