Sam,
Look at the fun that you'll be missing. Even if the main jet is right, it can't handle rapid throttle movement. Chad knows all about that. (cough - cough) I never could find the component source(s) to get mine right. Never was a Dyna jet kit for this old setup! I would have bought a couple if they were available. You'll just have to worry about something else. (like how the driver will perform) Looking forward to this fall. Good luck on the CR carbs!
Hondamatic 
Hi Jon, I figured you'd show up if automatic and carbs were mentioned in the same breath.
Ivan, you are surrounded by people with experience of both modern and period (old type) CR carbs.
Throw into the mix an authority on automatics and carburation and you have Jon (Hondamatic) Weeks.
When you get back to us, perhaps you'll fill us in on the type of CR and the reason for fitting them to an automatic.
Over the years several forum members have used the old CRs for racing for which they were intended for in the first place.
In the UK you have to use period carbs but in the US, the AMA found there was no advantage, performance wise over the old carbs, so allow the use of the modern ones.
The problems with the old ones are, they ARE old and replacment parts hard to find.
Both carbs are hard to set up but they do perform real well once set correctly.
We campaigned the 836CR that you see in my avatar for five years with modern CR31s with great results in classic sprints and drag races.
The one big problen we found with these instruments was the fact that you can't whack the throttle open fast, they require delicate control of both throttle and clutch to get the bike off the line quick.
When I decided to build an auto drag bike, I turned to the people that knew them and was helped in a big way by Jon Weeks.
Jon had campaigned autos for many years and set us up with a set of 34mm Mikuni CVs, they allow you to hit the throttle hard on the line without over fueling the motor and will give a great rush at the top end.
My advise is to sell the old CRs to someone building a CR750 replica who wants it to be period correct, you'll get a good wad for them and have plenty left over after buying more suitable carbs.
Sam.
Wonder if Chad will show up. (cough cough)
Poll