VG35 is used in almost every Nissan car so what makes them different HP wise?

I always figured, heads/cams/ECU tuning and a pluged up exhaust.

is it more then that or is it just a basic ECU fuel maps that changes the HP rating?

 

we use a VQ not VG

 

I knew that just wasnt thinking when I type it =)~

anyways VQ are used in most nissans still right?

 

yes, though the blocks are of different castings for some models (some are based on FW layouts, others on RWD layouts, so they are not all interchangeable)

 

So to answer my question on the differances....

Heads? Pistons? Cams? ECU changes?

 

heads - not that I am aware of
cams - again, same as far as I know for some of the enigne...cannot say for all
pistons - no clue
ecu - most definitely