Stock upper efi manifold porting

I built my engine with a Holley systemax lower efi manifold thinking that was going to be good enough. Now I want more and I don't want to throw out my investment in the lower manifold. Does anyone have details on opening up the upper manifold and porting them?

I ported the upper and lower on a car I had toll this spring, a 92 LX 5.0. the intake you have is aluminum, so it is very soft! Remeber that. Remove it from the lower and gasket match it when porting the eight runners. I used a carbide bit on a air die grinder, and followed that up with grinding stones using the same die grinder, and finished up with sand paper, going from coarse, (220) to fine, (600). Go as deep as your grinder will go. Not sure about your intake, but pay attendtion to the passage turns and always keep wall thickness in mind, dont wanna grind through...
On the thottle body side, hog out the opening to match your throttle body, 65mm or what ever your running. Same procedure. Go slowly, and remember to remove all flak and dust from the manifold with both water and compressed air before reinstall. Have fun!

Thanks, I did the gasket and EGR plate match last winter. What I was intereted in finding out was if someone had cut open the plenum and ported the entrance and horizontal legs of the inlet runners and then welded the plenum back together. Most of the losses, or pressure drop, occurs at entrance to a duct or runner in this case. I am guessing the stock, as cast entrance to runners from the plenum probably don't have real smooth radiused tranitions. I there could be some real gains to be had but I am not sure where or how to make the cut.[img]/phpBB/images/smiles/icon_smile.gif[/img]