Hello everyone, just bought a 77 L48 auto, and I am learning a ton here! I am going to be doing a full tune up and putting on a Performer 2101 as well. Couple of questions though, hope you guys can help!
first picture, I have a rubber hose attached to nothing...should I plug that?
Second pic...there is a tube extending out from the top rear of the carb that goes into the intake...and then another tube that goes to the choke assembly from the intake. Do I need this??? Thanks in advance!

 

I'm not really sure what you are pointing out in the first picture. There appears to be a blue cap on a vacuum nipple. The pulloff should be connected to that port.

In your second photo, the metal tubes go to your heat stove. They are required to make your choke work. To swap to a different intake that does not have this provision, you will likely need to convert to an electric choke.

It looks like someone already did you the favor of removing your EGR valve. Make sure that your distributor vacuum advance is connected to a manifold vacuum port (not ported vacuum).

 

Thanks for the reply! In the first pic, I was referring to that inch long rubber hose right next to that blue cap. It is just a hose with no plug.
The intake I am using does have the provisions for these tubes, however i was going to plan on using Fel Pro 1204's to block the crossover...should i just use regular gaskets then?

 

Save yourself the $200.00 on the Edelbrock and leave the stock intake on unless your just looking for the bling of an aluminum intake.
You will gain "0" performance.
Been there done that on my 77 L-48.
And yes the choke pulloff vacuum hose should be connected to the blue cap nipple.

 

I usually hang onto every advice you offer except now.
I disagree. At least with the 2101 you will ditch the EGR smog crap, get slightly better air flow and save some weight. Engine Masters did some dyno test on the 2101 but I don't recall the H.P. gain. That manifold also blocks off the hot air passage under the carb. A huge win-win for C3s.

But, its not worth $200. Sometimes news units go on sale for $160. There are dozens of used ones on EBay from $50 on up. Pick a clean one w/o oil stains.
When shipped with carb studs, vacuum port plug, coolant ports blocked and sometimes Intake bolts included, its always a plus. Shop wisely.

 

Looking at the two photo's the OP posted the EGR has been removed and capped.
The 77 L48 unless designated for California or High Altitude didn't have the air pump and exhaust manifold air tubes.
It did have the catalytic converter and EGR, that's it as far as emissions on a Standard Emission 1977 L48.
The 2101 does have the Hot Air Choke passage provision so, yes hot air under the carb.
I will agree the aluminum intake is significantly lighter then the cast intake.
You will also find the 2101 is a shade taller so if your running the stock air cleaner the hood insulation will scuff the paint just a little on the air cleaner lid.

 

I got my Performer intake for free...its very clean and for the cost of some gaskets, I thought it would be a nice upgrade.

 

Anything you can do to make the car lighter is good. But I'm not a big fan of doing things twice. Once you get your carb and tuning done (search on the forum for Lars, find his email, and email him for his timing and Q-Jet papers, and maybe get a copy of Cliff Ruggles' Q-Jet book), see how you like the car. A simple tune really made my 79 wake up. If you still don't have enough power, and need to pull the heads or swap a cam or whatever, you won't have wasted the effort of making your car 20 lbs lighter.

EDIT: Here's a recent thread with his email. The 1980 carb remains fully mechanical, with the exception of an electric choke.
https://www.corvetteforum.com/forums...-throttle.html

 

My 77.
As others have stated. clearly no point in putting on a aftermarket manifold and tidying things up a bit.
No exhaust crossover. no EGR. no choke. No Quadrajet.
And yes I'm still playing with it.

 

I think the 2101 is an excellent swap.....combine it with an electric choke kit and 1204 Fel-Pro intake gaskets that block the heat riser port. Use a 12pt ARP stainless intake bolt kit and put a little PTFE on the bolt threads.
The intake will gain some power itself....but it is not going to pull wheelstands.....combine it with a pair of Ceramic Long Tube headers/good exhaust and a good distributor curve with proper timing specs (E-Mail Lars for his paper on this). The three things together will show a very noticeable gain......

In your first pic that is the vacuum for the secondary pulloff.....chances are it is bad and Bubba disconnected it and capped the port. What happens now is the secondaries will open too quickly and cause a stumble. The air valve needs to open a bit slow for the engine vacuum to pull a "quick shot" of fuel before the valve opens to engine demand. This shot simulates a secondary accelerator pump. Chances are you have abog when the secondaries open right now.

Great thing about these mods is that if later on you decide to want more power......it will enhance a cam installation for max value. A well tuned L-48 with intake, headers and a 262 Comp cam will put a C3 in the 14's easy......this is pretty quick considering.......

If you like to learn and have fun.......the mods are the perfect thing to do and Hot Rod 101. I have done many in my life and everytime the customer is happy.

The pic below is a drawing of the GM vs. Performer vs. Performer 2000 on.

Jebby

 

In addition to having no secondary airvalve control due to the disconnected hose, you also have no choke pulloff operation, so your choke will remain fully closed upon engine start, resulting in a flooding or rich-run condition. If the pulloff has been disconnected because it's defective, you need to replace it and hook it up. If it's just disconnected because someone thought it prevented the secondaries from opening, you just need to hook it up. Test it by sucking on it.

If you do have to replace it, be aware that most of the replacement pulloffs do not have the correct bleed-off restrictor installed in them (if they have a restrictor at all). This results in no control of the secondary airvalve with a resultant bog going into the secondaries. You have to fabricate and install a correctly-sized restrictor in order to make the pulloff operate correctly.

Lars

 

I appreciate the response...so I plugged he vacuum hose into the port with the blue cap right next to it. The diaphragm immediately moved in. Dont know if its functioning or not, you mentioned sucking on it...

 

It's a good sign that it moved. I would still remove the hose and put a long hose on it that you can suck on: Sucking on it should make it retract, and you should be able to tell that it's not leaking. If it retracts, and it does not leak, it's good. If it leaks when you're sucking on it, you need to replace it, since this will be a vacuum leak source for your engine, whether the diaphragm retracts or not.