Thanks Chad an Zack,
With OEM header there is a lot more space to get the hoses out of the hot box. I trying to use some cheap ebay EL headers.
The best way for me to get the 2 scavenge line out is through the hole behind the water pump. With two -12 hoses, on would probably end up touching the header. I would put fire wrap on it no matter what.
I talked to John from Aviaid and said two -10 scavenge line would be enough. If I can get two -10 (5/8"OD) tubes through that hole, it solve my concerns. I want to go with steel tubing so I may have to get creative with bender without spending a fortune.