Not to offend anyone, But....383 stroker LS1's are obsolete. They were all the rage a few years ago....Especially Vette & F-body guys that thought their cars would flip over & burn if an Iron block was used
Why tear down a good engine just to use the block? When Iron 4" bore 6.0L blocks are widely available. Add in the fact you can build the long block without disabling your truck.
I vote for a 4" stroke, 4.030" bore 408 CI, Why build a smaller under-square engine for the same money. Plus you can run L92/LS3 heads with a 4" bore, Bigger valves, Better valve spacing, Bigger intake ports.