Fellows I'm doing an LSX Iron Block build 418 cu in 4" stroke,4"bore,20cc dish pistons,Will be running CNC ported LS3 Heads,And oh yea 76mm Turbo,Full 3in Exhaust,The only thing I have not nailed down yet is cam selection,I,m thinking of this whata ya think?
Comp Cams 236/240, .602/.609
115 LSA 112 ICL

 

Just a FYI but 4" bore x 4" stroke is a 402ci.

As for cam selection, what type of hot section will you have? Log, flipped stock manifolds, equal length primaries? Where do you want your redline to be? SC, EC or CC truck? Lots of variables.

 

I built a 4.03" bore x 4" stroke 427, except it measures 408. Comp specified my next cam to be 230-236, 115 lsa, with lift in the .577 neighborhood. It is supposed to peak at 6000 with my set up.

 

Thats pretty close to what I suggested.

 

Real close. When the cam help guy put me on hold, was he calling you?

 

03 hit it on the head.. If you want the best performance, what kinda exhaust set up you going to use.. That will help determine what dur-lsa you need or would suite you best..

 

with those heads ull need a badass LS/R cam something like a .236/.258 .624 .624 @ 115 lsa would suit u well

 

Ha, ya right.

Depending on what your goals are you could go a bit larger on the turbo. You say a 76mm but what A/R are you planning?
Based on the specs you posted in your first post that cam uses XER lobes, I am not to familiar with the new LSK lobes.

 

with that many cubes you are gonna wanna run a larger exhaust and prolly a larger turbo

 

He should be fine with a 76mm...but if you must, Precision makes a sweet 88mm billet turbo