Opinions on cam recommendation

My math gets an Ica of just about 55*. When I punch that into the Wallace Calculator, it spits out a CCP (Cranking Cylinder Pressure), of 172psi and a Dcr of 8.33, which is not too high for Alloy heads. You probably could have gone for a bit more CCP but I don't know about your gas, and it sortof depends on your elevation.
With pistons .013 ABOVE deck your Quench maths to .038 which is about perfect.
I think it will run gangbusters in that lightweight body.

IMO, a 106 LSA might be a lil tight for a 904; but I don't think you will notice, as, at WOT, those pizza-cutter 245s are gonna be on fire anyway. I think I would install it at no more than 2* advanced in your combo.
Like you, I would at least try the stock convertor.
Slam it in and go have some fun.