The 3 rows is good for up to 8 - 900 whp
So even those with the T-66 and the T-78 I think 3 rows is good to go
You don't need 4 rows for those turbo, It is overkill..
Just remember there are 2 kit for the 3 rows, get the one for single setup piping when you upgrade to single T-78, flow alot better.
To answer your question about piping.
You need to replace all the piping on the turbo side ( total 3 pieces) in order to fit the 4rows kit on the stock twin
Hope this help
Tommy