i have never seen a ivan's kit but i had a Dynojet kit and it didn't come with main jets.. all it had was different slow air jets... if you look at the top of the cabrs you will see a gold jet... those are the air jets(which i was to replace).. the kit i had gave me two jets for the two carbs on the outside and two different jets for the inside two carbs........................... ok i just looked at ivans website and saw a picture of the kit... the gold jets in the kit are the air jets... make sure you read the directions so you get the right jet in the right carb...
the drill bit is used to drill out the plug for the air mixture screw... you have to find a gold cap.. its circular and has a very small hole in the center of it... there is one on each carb... the air mixture screw is underneath that.. use the drill to drill a hole in the cap(becareful to not drill the screw on the other side)... once drilled look at your directions to see how many times you turn the air mixture screw(my kit called for 2 turns out)...
the needles are a little more tricky... you have to take the large black cap that covers one side of the carb, its held on by 3 screws... underneat that you will see a rubber diaphram(becareful they are east to break) remove that and and the needle will come with it... i use needle nose pliars to remove the cap that holds the needle on to the diaphram... now just take the needle off and just remember how it all goes back together... there will be a washer and a plastic spacer on the needle... and just reverse the steps to install.. and also remember the spring that goes under the black cap...
i would suggest doing one carb at a time for the first time... good luck.. hope this helps..