Been grinding on the stock iron intake for the Rallye 350 engine that is about to go in my wagon for break in and road time. This was something I wanted to do plus 1" spacer to compliment ported heads and big valves and future cam upgrades while remaining stock appearing. More plenum volume and the transition to port roofs no longer sharp edged, carb spacers and or carb adapters can work and flow proper now instead of crashing into the four holes especially driver side that was like 2 " deep.

 

Doing the same on my 70S, trying to make it look close to stock except with a dual snorkel ram air set up, even using the pie plate Rocket 350 decal to fool most, fresh big intake #6 heads, custom cam and I am also going use a Performer with the lettering ground off, a similar 1" open spacer and everything painted gold. Sleeper is cool in my books.

 

Opening up the plenum free of restrictions would also make the dreaded square-bore Holley adapter plate over the iron Q-jet intake actually work right at WOT. I don't expect much of a gain in a mild cammed engine but once I cam swap this engine later and have the 3.91 gears jammimg the 4 speed in the Rallye I think it will help from 5000-6000 rpm

 

oh and of course if I decide to do a small 125-150 hp spray on top of the 350
No spray pattern interference

 

If you got an extra wad of cash lying around you could put a W-350 intake on the car. It wont make any more power but it will take 23 lbs off the front end and work with the OAI set up with no mods. You will never lose money on a W-350 intake unlike an aftermarket intake which loses half of its' value the moment you take it out of the box it came in.

 

Oh I always keep my eye out if a W-350 or W-455 aluminum intake crosses my path at a garage sale, antique store for $20 but hasn't happened yet.. LOL I would likely just flip it for the money. I don't think I could take to cutting open one either if I had it.