I suspect that when you put the car on a Dyno that you will go up to around 130-132 mains. I'm running a similar cam but have 39mm Keihins with 155 mains which in Mikuni is around the 130-132, I have yet to run mine on a Dyno either but was able to pick up a few more RPMs by going from 152 to 155s. I did Dyno the A12 and when we got close the last change was going up one jet size, which was good for 4 HP, something I may not have done because the car pulled really well even though it was a touch lean.

As for the throttle cable I had a custom one made, this is fairly common for motorcycles, my buddy had enough of the parts in his shop to make one up.

I have very little experience with DCOEs but the sports racer guys who used A-Series engines picked up 10 HP by simply switching to FCR carbs.

Tom