I want to go studless, what's the max lug size I can go?

[Skeeterzx225]

I'm looking towards replacing my Ripsaw with 96 studs up the middle with an IceRipper track, what size lug can I use without worrying about hitting the heat exchanger? 1.5? or stay with 1.25?

I ride mostly trails, but also hit lakes...

 

[Zakre]

1.5 will clear, but i wouldnt want studs that close.