I'm thinking of using a 200-4r trans in my Concord behind the 416. The 416 is going to be pretty strong running a rather large solid cam. The trans has been built to take a lot of power, so I'm not concerned about the transmission. It's a BowTie Overdrives Level 3 200-4r. The issue I have is with the carb. Huh? Let me explain...
 
To use the OD trans, it says in the install kit instructions to use a vacuum secondary carb. I had planned on running a double pumper carb in the 850-950 range. If I have to go with a vacuum secondary carb, the largest I've found is a 750. So, my questions are:
 
1) Do they make a bigger vac sec carb than a 750?
2) Do I really HAVE to run a vac sec carb with the GM OD trans?

I was thinking the same thing about contacting them. I don't remember if it said why you needed to use a vac sec carb, but I remember it said it in BIG letters.
 
The 200 does have the TV cable. Bow Tie Overdrives has a thing they developed to make sure it works correctly somehow.

I didn't see anything on Summit, so I'll check Jeg's. Thanks, Ralfy!

Quote from imacarfan2 on 02/09/10 at 02:07:08:

 
What is likely, since I'm assuming a transmission computer is not part of the kit, is that vacuum secondary requirement is connected to how the lock-up convertor comes into play. Probably uses a vacuum unit to control the lock-up, possibly in overdrive only similar to how the first pre-computer lock-up Turbo 350's worked in top gear. Also since the tv cable is the controller for shifting, line pressure, etc. and is tied into throttle lever position at WOT then a vacuum secondary carb probably ensures smooth shifts controlled by the cable and kickdown would be less abrupt with a carb that opens the secondaries based on vacuum instead of throttle position. Just a guess at how things work.
 
Steve