This might have been asked before, but I couldnt find anything on a search so my apologies if this has been answered before. So I am looking at building my engine and the question I have does the Edelbrock Performer RPM manifold with a carb fit under the hood of a 1st gen Firebird? The guy I am talking with to build my engine is saying he doesnt think it will fit without modifying my hood. Please, can someone settle our debate about this and also maybe provied some pics of this? Also, can you list any reasons as to why this wouldnt fit, like the combination of that and a certain carb...etc? Thanks all! Happy Monday to all!

The regular Performer manifold is an aluminum copy of a RA IV Pontiac manifold (something like that) so everything is comparable to OEM. But the Performer RPM places the carb about 1.5 inches higher. I am not sure about clearance with stock air cleaners, but I strickly avoided the RPM on purpose so I could install a reproduction Ram Air system (and sacrificed some HP).

Yes it does no hood issues here... Close but fits

Yes

I have one w/a 1.0" n2o plate.
Oh, and a 1.5" drop base air cleaner.

I had a performer on mine with a spacer and it fit. I put an RPM on during rebuild and didn't fit with no spacer. I had to use a drop base air cleaner as Mr Warrior did.

Thanks for the encouraging info all! Gives me an option now. Thanks Goose for the pic, as it gives me an idea of the clearance. Do you also use a drop base air filter? Warrior and Bluebird, what carbs do you have and does the drop base interfer with any of the carb linkage or anything else on the carb?

Mine is an Edelbrock EPS 800. No interference with other parts, but mine isn't exactly stock.
If you have your engine still in your car measure your clearance and check what you have now. You can make a balloon out of tin foil and close the hood, the hood will squish the balloon to whatever your clearance is. Put some soft paper towel or cloth on parts so the balloon won't scratch. I think I used strips of dumdum.
Unless you're building an engine with better flowing heads, and a cam that gets you your power at a higher rpm than stock, the Edelbrock performer will work just fine for you. I use the Performer RPM but my displacement is 463 CI, the heads flow a bit more than stock at 307 cfm, and camshaft is bigger than stock as well. The Edelbrock performer is designed to work from idle to 5500 rpm and the Edelbrock performer RPM is designed for 1500 to 6000 rpm. Depends on what your intended build and usage is. The performer will fit no problem.
Just a thought, I could be wrong.

Thanks for the info Bluebird! My engine is not in the car so I am out of luck there, and yes, my engine is getting stroked to a 463 ci also and using Alumn heads and a bigger Cam so I need to use the Performer RPM. I am guessing my engine should sit about the same height as yours in the engine bay once I am done and it is installed. You mind posting a pic of your engine and engine bay? Thanks man!

I lost a lot of files when this computer went kaput but I have a couple pics. The triangle air cleaner sits about two inches higher than the round one. I may be able to take a few shots tonight if you want.
What are the specs of your new build, bore,stroke,cam,deck height, deck clearance,piston construction shape,rods, rockers etc.?

Oh yeah, you have to modify the throttle bracket with the taller manifold. The stock brackets sell for a ridiculously high price so maybe get/build another and save the original. I wish I did but was too anxious to get the motor in.

WOW!!! Bluebird, that is a sweet setup you have. Can you tell me a little about yours? HP, torque, cam? I dont know all the specs on mine yet as the builder and I are still working out the plan, but I know it will be bored the .030 or .035 which ever is required for the 4.250 Stroke for a 462 or 463 ci and all forged parts and going to use the scorpion endurance rockers so I can hopefully use my stock chrome valve covers since they are suppose to be shorter for that purpose. Looks like I am going to go with some "E" alumn round port CNC chambered heads. The cam will be a custom grind Hyd roller, but I dont know any of the specs yet from the builder except the operating range will be about 1500 - 5800 RPM's. I wont be using my throttle bracket as I stopped using that when I switched over to a 2004R OD tranny last year. I have a lokar throttle and bracket set up which should still work as it bolts up to the carb bolts. I am also interested in your Radiator overflow tube/bottle, whatever it is. What is it and how is it mounted? Wouls like to see some closer pics of that if possible.

I did not have to modify the original throttle bracket. I can send a photo if needed.

The foil trick works great...and I also use a 1/2"spacer ...and dropped air filter .



DO NOT USE AN AFTER MARKET VALLEY PAN. It's like sticking a straw into your oil pan.

Bluebird...NICE!

Ordy don't worry about stock covers and rocker height. Ames has a listing for some thick rocker cover gaskets that give you the clearance you need.

Mr. Ordy
Are you using the Chev length rods and journal size? After I re-did the seal groove and assembled the third time I got 535HP and 600FP. I'll send you a PM with the spec sheet. Over flow can is from the local tool store, KMS Tools, but they sell them everywhere. Look nice but one has to take the cap off to see the fluid level. This one holds the same amount that the rad and engine overflow. It's full when hot but empty when cold. I still have to take the rad cap off to see the fluid level, it's always full. I made some brackets from stainless steel. You're better off to go with a plastic can as you can see the level at a glance. I'll send some pics when I get a chance.



Mr. Bronze Bird,
Your car is just as nice under the hood as it is with the hood closed. My bracket worked with the Performer but I had to shorten it with the RPM. I also tried an aftermarket valley pan but it was junk so I spent a few hours hammering out the stock one.

Mr. Goose,
Looks like oak?
I needed the tall covers to clear my rockers.

I posted earlier this morning at home, but now I come on here and my post doesnt show. Strange. Anyways, I posted a question to Bronze bird as to what he meant by saying "DO NOT USE AN AFTER MARKET VALLEY PAN. It's like sticking a straw into your oil pan"? I am not sure I understand that.

Also, to Goose, I am trying to lkeep the valve cover height down as I am trying to be able to fit the stock valve covers between or under the stock brake booster. I currently have a whole new brake system, but I am trying to avoid having to buy a smaller booster just because of the valve covers We shall see what happens.

Bluebird, it should be the 6.800 lenth rods and the Rotating Assembly 4.250" Stroke x 3.00 journal... not sure what the Chebby journal size is?

Both Bluebird and Bronze bird have awesome looking birds, inside and out!!

[quote=USMC_Ordy

Also, to Goose, I am trying to lkeep the valve cover height down as I am trying to be able to fit the stock valve covers between or under the stock brake booster. I currently have a whole new brake system, but I am trying to avoid having to buy a smaller booster just because of the valve covers
[/quote]

Think you misunderstood, that exactly what they were built for... Stock covers but running taller roller rockers underneath. I too have a full size booster and have the same clearance issues. These are a $25 fix to solve that issue

ORDY, the after market valley pan does not have sufficient baffelling associated with the PCV valve to prevent oil being sucked out of the engine, into the intake manifold. I'm talking a quart every 100 miles!!!

Reinstalled my stck pan and no more issues.

Are those installed in your picture above? So how much room do you have now between the booster and valve covers? Yea, I was thinking those gaskets in the pic was those metal pieces that raise the cover up higher, but those are thick gaskets... got it brother!! Semper Fi Devil!

DANG!!! Really? So you are saying that if I use like a Tomohawk stock reproduction valley pan like this http://www.jbp-pontiac.com/images/DressUpMIsc/pontiac%20valley%20pan.jpg then I will have problems? Or is it the billet type one layer type pans that you will have problems with?

That Tomohawk pan looks pretty dang good. The chamber maked the diff. The billet type is the one that has the oil suck issue.

You will likely have to grind the edges so the intake will fit. That is, make room where the intake contacts the heads.

From what I understand the Tomahawk cover has factory style baffling, so shouldn't suck oil.

Cool Bronze Bird... I got a little worried when you first mentioned this and feel better now as the tomahawk is the one I am going to use on my build. Thanks for passing on valuable info!

Here is another question that I was told was a potential problem using the drop base air filters. The distance from the Top of the Carburetor's Air Horn and Vent to the Bottom of the Air Cleaner Lid is Crucial. If the distance is TOO Little then the Carburetor will Starve for Air and make the Air/Fuel Mixture go Rich at Wide Open Throttle. Does anyone have this problem and also does anyone use a drop base type filter that can breath through the top like this http://www.summitracing.com/parts/edl-43661 and if so can you please post a pic of it in the car? Thanks.

That's the pan I bought, but the fit was so bad I sent it back and reused the stock one. A lot of debris gets into the baffle over fourty years so one has to be sure to clean it out well. I had to bash, I ment massage, the pan on one side for the roller rocker clearance.

I'm pretty sure the drop base flows enough with the three inch element and curved pan design. Airflow accelerates as it moves toward the horn.

I have a fuel/air ratio gauge in my car, when I get a chance I will make a run with the lid on then another with the lid off and compare ratio. Or maybe do it in the garage. I have the same ratio now as was on the dyno, they have a monster air inlet so now congestion on theirs.

Which air filter are you running Bluebird? The round or triangle one in your pics? That would be interesting info to know about the fuel/air ratio. Thanks!

I would also be interested in the outcome of the A/F test at WOT using the drop base. Also need to know how much clearance between the under side of the cover and the top of the carb. No flow thru filter top, I'm assuming. I was running a spacer under the qjet and an RPM and had to run a drop base and go to a 2inch filter to fit under the hood. I don't think there was more than 1/2" clearance fo r air flow.

I'm sorry, of course I didn't have to bash the valley pan for rocker clearance but for roller lifter clearance.

I'm using the round drop base cleaner. It's a Moroso with a three inch by fourteen inch air filter element. The triangle one is an Edelbrock with a three inch washable K&N style element, non-drop base. It cleared at the nut but not at the outer edges.

There's two inches from the top of the carb lip, the part the base fits around to the top of the filter element, a bit more at the center of the carb, and three quarters inch from the top of the element to the bottom of the lid at the highest part. It's slightly less where the center bolt goes through. From the top of the highest part of the base to the top of the filter element is 1-1/2". So I guesse we are looking at 2-3/4" right above the carb and 2_1/4" around the carb. Or, it starts at three inches at the inside of the element, tapers up to 2-3/4" around the carb at the smallest clearance then widens out to 2-3/4" above the carb. There is slightly less clearance above the choke plate. I have that wired open but plan to remove it entirely.

It'll be a while before I can do a WOT comparison on the street. We're still cutting 100 foot firs off the roads from the latest windstorm. I can try one in the garage but I don't know how useful that would be without a load on it.

Forgot pics

Great pics and explanation Bluebird! Thanks!! That really helps me out and shows what it really looks like with the amount of space between the airfilter lid and carb opening.

With all the salt and sand on the roads over here I wont be taking the car out for a while so I tested the fuel air ratio with the air cleaner on and then off in the garage. I made two runs with the air cleaner in place then four with it off then two more with the air cleaner on again. I took it up to 6,000 rpm and let it stabilize each time. There was no more than 1/10 of a point difference between all eight pulls. Pretty much the same for the cleaner off as with the cleaner on. I don't know how much if any the secondaries were open but I'm sure it's drawing enough air in at 6,000 rpm to use the test results.

Thanks for posting the results of your testing. in the garage?

No I didn't wear SCUBA gear,
My garage is too small to park the Firebird in and also use it for other projects. Rather than push it outside every time I need to do a job on something, other than the car, I built a shed-roof Bird house onto the side of the garage. I made it with doors on both ends. I can open both ends and run the car without a death wish.

That's a nice little set up you have there!!

Very nice!!

Well I'd rather have it in the garage but this way it stays clean [under it's cover] I'm not going to smack it with a chair or piece of pipe and I can access the beer fridge. It's not quite wide enough to open both doors fully but better than having to move it in and out of the garage.

How about it USMC_ordy did you go for the RPM?

Yes, I have decided that I will go with the RPM, but it is part of an overall engine build so it hasn't been purchased yet.

Yes a performer intake will fit under a stock hood. I have a 68 that has an edelbrock performer and edelbrock carb. I ran an edelbrock deep dish air cleaner with a banjo fuel fitting on the side of the edelbrock carb. I was nervous the first time I closed the hood, but it fits fine.