The metal hose in back of block, is it safe to keep the stock LS or should I

change it from my GSR block. ( LS only has one cooling line, GSR has two

lines). What should I do?

 

I believe it has two because it uses one for the oil cooler on the back of the block.The gsr has the oil cooler and the ls doesnt.If you dont put the oil cooler on you need the water pump pipe with the two lines.If you dont use the oil cooler use the single ls pipe.I put the stock oil cooler on my lsvtec.It warms up the oil faster when you first start your engine and it helps regulate oil temperature when the oil gets to hot.It acts as a heater cooler.

 

does the second hose fitting need need to be hooked to the heater core hoses?

 

follow clooners advice...exactly what i did on my ls/vtec and its running very nice!