My buddy ported some 462 fuelie heads out, when a local shop tanked/rebuilt them for him, he mentioned that he ported them and the guy at the shop didn't seem to enthusiastic about possible power gains.

How much does mild porting helping? Like...just removing casting imperfections that block the intake valve and such...

I didn't even bother porting my vortecs at all....

 

Your discription of the amount of work done to the ports is very vage.

Keep your expectataions modest.

Here is a link to some typical mild/moderate porting
results on some popular heads including the vortecs and 462's.

The area just under the valve ("pocket") and the valve guide boss contour is critical.
So is the valve job.

http://www.kendrick-auto.com/head_flow_figures.htm

10hp on a stock or near stock motor
40+hp on a built up street racer.

A head like the 462 casting shown is capable of supporting the horsepower nessessary to run mid to high 12's.
in a 350 based third gen.

 

Yea, we just ported where the valve pocket is, there was alot of casting that stuck up where the valve opens, we just ported out the extra material and rounded it out.

That link was real helpful thanks. His 462s probably flow near my Vortecs @ .5 lift, but from .2-.4 lift the Vortecs really shine in comparision.