I'm trying to find out if the vq37hr and the vq35de have the same deck height/ block height and if the main journals and rod journals are the same diameter on the crankshaft... If so I would like to know the possibilities of swapping the pistons, rods and crankshaft from a vq37hr and into a vq35de...

 

no, and no.

Just get a stroker kit for the de (BC, JUN, GTM, Cos, etc.)

 

what kinda power do the NA stroker kits make?

 

Depends on many factors, including displacement--I'm no expert but maybe 50 whp with supporting mods and porting for something like a 4.2l stroker kit.

Contact some reputable vendors on this site for more accurate info on power and pricing--they would be better able to tell you than me (Sam@GTM, Shariff@forged, Julian@MRC, etc.)