Ok here is the deal im getting a brand new type r shortblock and putting my old gsr head thats going to be port n polished and has ctr cams in it and a skunk 2 intake manifold. currently it has a stock gsr ecu ad i am planning on going with crome to tune it. my question is what should i do because of the break in period with the new shortblock. should i just run the strock ecu untill it is broken in and then tune it?

 

Tune first, then break in. Always. Never drive a car until its tuned, unless you like melted metal.