Don't get me wrong...
I TOTALLY love the I6, and think it's one of the most dependable engines GM has EVER put together.
But, I think you're going to run into problems...
First, getting it connected to the Transmission. I know of no adaptors which do this, so, you'll probably have to have one made...$$$
Secondly, those 6's have a different torque/power range than do the 8's.
I think you may be disappointed (like Zora mentioned) in how the vehicle performs. This coming from the Transmission Gear Ratios being set for the higher RPM/torque ranges generated by the 8 cyl engines. It's possible that you may be able to adjust the Differentials Ratio down some, but that's going to cut into your higher speeds, and remember any change in this is X2 (front and rear).
Just a tip here...
On the clearance (as previously warned) many times when a longer engine is installed, one can do away with the Reciprocating Fan completely, and go with Electric Fans in front of the Radiator.
HA, if this is the first engine swap you've ever done, you got a real experience treat ahead of you !
GOOD LUCK
