Originally Posted by F-BIRD'88
What is the date code on your vortec heads. It's stamped on the exhaust side flange, on a machined surface area.
I don't have any pics of my ported vortec heads. I did them quit a while ago. They are on my 406.
2.02x1.60. I never took any pics of those.
With the stock 1.94" valve intake port you are best to just smooth and generally clean up, whats there.
The form under the valve is quite good. At least on the early Canadian made heads. 1996-2000.
The later mexico heads are smaller, low less in stock form and can use dome more work.
How you port thee heads is dependant on how they are going to be used.
The port shape you want for a big cam big valve lft "race" is different than the port and bowl shape thats best when the valve stays relativily close to the seat. small moderate duration and lift.
The vortec head has really good low lift flow in stock form. for a mild mtor do no remove the critcal funnel shape of the bowl under the valve job.
You can generally streamline the guide boss so air can go around it.
Flowing the garden hose thru the port will help you see the natural flow path on a SBC head.
Post all the stamped numbers that are stamped on your heads. May need a light and some emery paper to see them.
On the exhaust flange.
The numbers I found are: 10, 062, 8, 18, M127, GM-D, 12558062. Are these what you need?