If you’re boring your own manifold, a die grinder or high-speed drill can be used with a grinding stone or sanding drum to bore the manifold from its 63mm stock size up to the outside edge of the circle you traced in step 1.

Be sure to remove any old gasket material from the mounting surface. If you are using a new intake manifold, disregard this step.

Remember that it’s better to open the hole up too big than too small. It’s very important to thoroughly clean your manifold after boring it as any aluminum dust left in the manifold could cause damage to your motor.

Blow out as much dust as possible with compressed air before cleaning.

Next, flush out the remaining dust. Allowing water to flow through the manifold for a while will help to carry out debris that may not have been removed earlier. Make sure the manifold has thoroughly dried before installing it back on your motor.

The same steps should be followed for the PRB & RBC style intake manifolds. (PRB style shown)