+1 on the hydro-lock
If you put it in the wrong place and you hit a puddle or in my case your in a flooded car park you will root your engine
http://www.skylinesaustralia.com/forums/St...p;hl=hydro+lock
go to the last few posts to see all the damage, photos and everything.
Be Careful!! - in saying that i put mine in a very stupid spot, it was cold for sure but too exposed to water and to low too the ground - as far as performance, meh i didnt notice much, get someone who has done a dyno run before and after.