Putting a real Pontiac engine in a 91 firebird

I'm looking for any advice/warnings/ or general information on putting either a 400 or 455 pontiac engine in a 91 firebird. Can this be done? if so, what am I going to need. Will I be able to bolt a 6 speed trans to it? I've never seen this done so any information would be greatly appreciated  

Now that you mention it, I don't think I've ever seen even a GenI Small Block Chevy in one.....  How do you set the timing on a mechanical distributor once the engine is in?

If you got excellent fab skills it shouldn't be too tough.  For the six speed you'll have to find an aftermarket bellhousing to get the input shaft the right distance from the crank.  And make sure your crankshaft is drilled for the pilot bushing/bearing.  Check Mcleod, Kesler, etc for the bellhousing.  You'll need hella beefed up springs in the front end too for the extra weight.  
-
The Silver Buick- '77 Skylark coupe w/ a Fuel Injected Buick 455&TKO-600, '72 Centurion Conv't - 455w/TH400, '67 T-bird 4Dr (suicide) w/428&C6. Needing to replace a '69 Firebird 400.

http://www.bangshift.com/forum/index.php?topic=6189.0

Thanks for the info. You've given me a pretty good starting point. The timing shouldn't be a problem since the computer will be gone. This is the third gen firebird so half the engine isn't under the windshield. Thanks again