Cummins 4bt or 6bt
 

G'Day guys. Im in Australia, and am looking to do an engine conversion into a Nissan Patrol. I am going with a Cummins, and havent decided between a 4bt or a 6bt.
I dont have the extra space for a full engine rebuild. Cummins support is strong over here, but there is no after market support at all.

I am after a fully built engine, ready to drop in. My knees are totally shot, and I need an auto transmission to get it rolling as well. For that, Im thinking of an Allison 6 speed.

I want a 4bt capable of putting out 350bhp, or a 6bt that can put out 500bhp, but both will be tuned down about 20% from those numbers. I want a transmission that can handle those numbers. If you have another suggestion on a tranny, Im glad to hear it.

I know this wont be cheap. Thats ok. I plan on owning the vehicle till Im too old or too dead to drive it any more.

There is no rush. I am looking at starting early in the new year.

Cheers guys
Mark.