You will want to cut out for a ridge vent at the peak. Cut the sheeting and remove 1 1/2" on each side of the peak and if you have a hang over on the gable you can stop at the gable wall.
I you need 1 1/2" under the sheeting for air so the top of the blocks between the rafters have to go and there is not need for those blocks so if easier just knock them out.
If you can clear a path from the soffet for 1 1/2 inch air passage next to the sheeting., you can go ahead and do the roof. Or you can consider insulation between the sheeting and the roofing with foam board.
I you need 1 1/2" under the sheeting for air so the top of the blocks between the rafters have to go and there is not need for those blocks so if easier just knock them out.
If you can clear a path from the soffet for 1 1/2 inch air passage next to the sheeting., you can go ahead and do the roof. Or you can consider insulation between the sheeting and the roofing with foam board.