I was checkin out the turbonetics y2k 80mm for my engine project and noticed the turbine outlet is 5" across and looks like it would take a v-band clamp. Could that measurement be o.d. of the clamping area and would that mean a 4" downpipe would be enough? Just curious because I think a 4" dp would be a pretty tight fit and a 5" is just out of the question . Any help is apreciated.
BTY, I am looking at buying a 2000 ls1 to put darton sleeves in for 440ci, is this a bad idea to go with the aluminum block and FI? I am having a hard time locating any iron blocks for cheap, sleeving the ls1 also adds a little displacement over the boring the iron block. Any opinions are welcome.

 

An iron block is cheaper than a Darton sleeving upgrade to a LS1 and is stronger for big FI power. I would stick with iron. If the weight penalty is the issue... just run a little more boost