Got my head off now and was looking at opening intake ports to match the gasket. How far down can I go in the head before I get to thin and the same for plenium. Got to replace 8 bent intake valves first Merry X-mas

Hello Paul.

You actually don't need to remove that much meat in order to match the Ports to the Gaskets.

I always start by using a Black Marker around the Port and scribe a line using the Gasket as a template. Do that on both the Head and the Manifold (intake side). You should have about 2 or 3mm of material to remove on the bottom and almost nothing on the top.

An other good place that is good to clean up is inside the Valve Bowls and inside the Runners to remove the Casting defects and any sharp edges. Run you finger inside the bottom of the Intake Ports, you'll feel a bump about 3/4" before the Valves. That is a good spot to clean-up.

You don't need to go too deep inside the Intake Manifold. Match Port to the Gasket and remove the Casting defects with a 220 grit Sanding Drum. That shoud be sufficient.

Exhaust side is pretty much the same. You will need to remove more meat to match the Gasket. I like to leave about 1/8" around the Exhaust Port so you have a larger mating section at the bottom of the Port (Exhaust Manifold), that one is hard to explain. You can go a little closer to the Gasket but again it does not leave too much meat.

Like I said; Start by marking the Gaskets size and have a look at what you need to do. Some are more adventurous than other. Only place to be carefull at is actually at the dividers. There is a Water Jacket that runs inside the Dividers. You can safely make them sharper but don't be too crazy. Just be really carefull with the Exhaust Dividers...

I hope that can ansewer your question.

Ghislain.

Thanks for the info on water jackets just what I'm looking for before I start grinding, Paul.