Ive taken the plenum apart on my 86 lb9 Z and am wondering what there is to port. I know the big wall in front has to go and noticed a some gasket matching is needed on the runners. Should i just gasket match and not try to enlarge the runner any? With stock runners i know im limited but can i do any more to 'em than just gasket match? Show pics if you have them, thanks.

 

it wouldnt hurt to make the runner ports, or the throttle body ports larger.

 

Ok, the EGR walls can go. And if you look at the TB openings, you will see the side walls are obstructive. You have to radius that because the wall is very thin around there. gasket match the runner ports, but making them bigger then the gasket is really worthless since the gasket will interfer with the air flow. gasket match the runners as well. Polishing the plenum is a bad idea!! well if you want the look but it will retain a lot more heat. Just an FYI. i have a few bad pics... here ya go. ill email you the rest if you want them.

 

See these posts including a link to Vader's pdf article on the topic:-

https://www.thirdgen.org/techbb2/sho...porting+plenum
Time and materials cost for porting TPI manifold, runners, and plenum?

https://www.thirdgen.org/techbb2/sho...porting+plenum
Need advice on porting/polishing plenum

https://www.thirdgen.org/techbb2/sho...porting+plenum
Urgent help needed on Plenum porting

https://www.thirdgen.org/techbb2/sho...porting+plenum
ported plenum pictures