My 69 Firebird 350 has an Edelbrock Performer RPM intake manifold that the previous owner put on. Everything I have read tells me that this intake is designed to work at higher RPM's and that the Edelbrock Performer would have been a better option. Fortunately he did not get rid of the factory cast iron intake so I still have it. Is the only advantage of the Performer weight ? Which intake should I run with ?

Run a Performer, if you want the look & lighter weight of alum. If not, run the stock iron.

Agree. Ditch the RPM for sure. It's not a race car so you really don't need to save every once of extra weight. Run the stock intake.

The RPM is a 4bbl intake. The stock iron should be a 2bbl intake. You will need a carb too?

A '69 350HO used a Q-jet intake, same as was used on '69 400's & 428's.

Yes, but no idea what the OP has. Probably a standard 350, which is likely why someone stuck the Performer RPM on it.

I have a 350 but I am assuming that the original owner in 69 had the dealer install a 4bbl intake & Q Jet carb as the numbers on both are correct for 1969. For this reason many people mistake it for a 350 HO as standard 350 only had a 2bbl. The RPM was put on by the guy I bought the car from and I have the receipt where he purchased it from AMES. I am lucky he kept the original intake and gave it to me with the car.

Factory intake for the win!

I would be curious to see the difference when/if you put the iron intake and q-jet back on. You would think the guy who put the RPM on saw some improvement, or at least equal performance?

Probably not but its hard to admit it when you just blew $250 on a shiney new intake.

So, unless there was a cam change at the same time, peak horsepower for that engine is at 4,600 RPM. That intake likely improves performance higher up in the rpm range, but that engine doesn't have the camshft to get there.

I am not sure why he chose the RPM over the Performer. My guess he wanted aluminum intake for look and maybe weight. As weight is not a major concern for me I am going to put the original intake back on.

I did a lot of reading on intake manifolds over the last two years. The stock four barrel manifold is suppose to out perform the Edelbrock performer intake. The Edelbrock RPM will out perform the stock intake as long as you have the rest of the motor to go along with it.

FWIW the RPM worked the best on friends 400 with #48 heads and 744 cam with a holley 850 DP
Tried all the intakes out there.
This doesn't hold true on every engine but you can't go by everything you read on the Internet.