Manual To Automatic in a 67

I have a 4 Speed (Rock Crusher) in a 67 C-10 that is used for street fun. I'm looking into a Turbo 350 or 400 and would like the opinions of anyone who is into street/strip to the pro/cons of the swap. As well as help in understanding what is involved. I can build a motor but, I have never did a tranny swap of man to auto. What will need to be done. I know each job is a case by case but what is the norm.
Thanks for any help/ input.
David
By the way, the engine is a 383 Stroker with 452 HP (fly wheel) 495 TQ (fly wheel)

Is this an M22 rock crusher, or is it a "compound low" 4-speed? I think either way, if the rearend has the original gearing, you'll either have a 4.10, or something in the "mid-4's" gearing. If I'm not mistaken, your trans may be "floating", with the bell-housing mounted to the crossmember...is that correct? If so, you may have to find or make a trans. crossmember. Also, if you have a compound-low trans, you'll have to shorten the driveshaft, and get the correct yoke for the Turbo trans. Running a trans cooler and lines is simple, and installing an aftermarket shifter is a piece of cake. But of course, with an automatic, there will always be some slippage, so your engine will run a little faster...even faster if you use a higher "stall" converter. And also you'll need a "400" flexplate, which is sold at most performance shops. Why are you switching to automatic? Just curious :).

Thanks for the reply.
I have been told by many different people including tranny shops that it is the true M 22 Rock Crusher. And yes, it is floating. As for the reason why I'm switching to an auto is that I just wanted something new. I have not made my mind up on what to do. I drove my buddies 67 Camaro and my brothers 86 S-10 just recently at the track and loved it.( both 10 sec 1/4). I will have to go with a 2600 (at least) stall and most everything else will be learn as I go. I'm looking into anywhere from 4.11 to 4.56 gears as of now with my 4 speed. The truck is only driving around town and when it goes to the track it is only a 1/8 mile track.
The truck is getting a major overhaul right now and the guy says he can do it all. As he makes a living updating old cars and trucks. But I would like to build as much as I can. I do not like driving someone elses creation.
Just looking for the pro's / con's.
Thanks again,