I bought an fc a little bit ago, here are the specs of the engine.
Engine
• S4 6port engine with 110k miles
• Warborol Fuel Pump
• 680cc Primaries Injectors
• 1000cc Secondary Injectors
• Turbo T4 - 1.10 Hot Side .60 Cold Side
• T4 Turbo Manifold w/External Wastegate (12psi)
• Modified/Ported & Polished S4 T2 Intake Manifolds
• GM 6.0 Coil Conversion
• Microtech Lt8

This engine has lost compression and is in need of a rebuild. My question is, I have housings and all internals except irons off of a 4 port. What of this should i use in the rebuild, or should i go ahead and get irons and make it a complete 4 port engine. Comparing the two it looks like the 4 port exhaust is much smaller, not sure what gains or lost that would give since the 4 port is designed for a turbo. The 6 port actuators have been removed on this motor. The guy claimed that it made somewhere around 400hp with a vmount intercooler setup.

Alot of mods have been done to this 6 port to make it run a turbo smoothly, so should I keep it how it is or will i have a better motor another way?

 

Looks like you have a bit of a mess on your hands...

The lower intake has been modified to fit the 6 port engine. So for starters, to go to a 4 port, you will need a new lower intake. Not a huge deal.

The exhaust ports on the 6 port are larger because they have been ported.

Going to a 4 port basically means porting it a little (that large of a turbo will require a street port to have reasonable response) and then swapping the the LIM.

Also, it would be nice to find out why the original one blew. If it was just a problem with the tune, then that's fine because you'll be retuning anyway. But if it was something else like a failing fuel pump, you may blow another engine.

 

I have the intake manifolds, I just need irons, unless there is a way to keep the 6 port irons and swap out the rest id have to go with a full 4 port. To my knowledge the fail was because of a tuning problem. With that said, im not sure what to do. I could keep the current engine the way it is and simply rebuild it, or get irons for a 4port and street port it. Rebuilding the engine the way it is seems the simplest to me but I dont want more problems from it later down the road, and I dont necessarily have money to get irons.

 

I'm confused by your question. Are you asking if you can use 6 port rotor housings with 4 port irons? Yes, you can. And vice versa.