It wasn't too hard to do. Nothing pretty, but I did knock out the EGR blocks, and also cut and smoothed down the cast around the runner holes too.

First time i've used a dremel tool, but overall I would say anyone could do this easily. Tough part is putting everything back on the car...

 

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very cool pictures

 

Thanks.

 

I would do a bit more work on the sides behind the TB holes.....smooth it out some.....

 

Let us know how it runs after you put it on. I have heard this doesn't do much for a 305. I'd like to know how it works out for you because I am considering doing this when I do my heads and cam.

 

Every CFM counts. You might want to enlarge the TB bore more as well as the runner entries.

 

what would porting the plenum and the space behind the tb do for power? and how exactly do you port the walls inside the plenum?

 

It just removes airflow obstruction. Right behind the throttle bore, there are these two little walls that stick right into air travel path... they get knocked down. Also, where the air enters the runners (runner entries) can be enlarged. Basically, it gives the plenum a more "throttle responsive" interior. It's good for it too - stock cars benefit, and modded cars of course benefit more.

 

My car is pretty screwed up, so I'm not sure if it will go back on or not.