I am putting together a 2000 ls1, in the gathering parts stage now.
I purchased a holley 4779-9 750 double pumper off of ebay for $250.00
said it came off of a supercharged smallblock, thats what I know.
My question is, will it start and work? I know nothing about carburetor's.
I am wondering if they had to change things inside, is there a standard I could get parts and put back to "normal" ? I am looking forward to learning, I know
I could send it off to a pro but I wouldn't learn anything that way.

Now, what is the opinions of the professionals about how my vehicle will run when completed, here are parts I have
2000 LS1 5.7 stock (fresh) with 243 heads and 918 springs, no work done.
cam duration@.050 intake 227 exhaust 239
max. lift with 1.7 rockers intake and exhaust .551
lobe seperation 108
stainless works 1 7/8 long tubes
vic. jr.
750 carb the msd 6010
T56 trans.
3.73 rear gears
315 35 17 rear tire
1985 s10 weighs 3100 with stock engine, me 188#, and 20 gallons gas
I said I am a nooby so be easy on me.
Thanks in advance for any feedback

 

No 100% sure but a supercharged carb should have same components as blow thru carb so....will it run I believe so.just beefed up in case air is pushed or pulled thru it.should b fine maybe others can chime in

 

So maybe just try it and see, sounds good to me. Thanks

The thought of the second part of the question didn't quite make it to my fingertips
like I wanted, the question I wanted to ask was how do you think this cam will act
with the rest of the parts, or is this cam worth a crap?

 

The combo all looks pretty good. As for the carb, I like to start a new combo by returning it to factory calibrations. To see the factory jettings and calibrations, refer to model number 4779 in this document:

https://ac17cb7e3cc3506f0d23-7386afb...al_listing.pdf

Carbureted LS engines often suffer from a bad lean stumble off idle. If you experience this, you will likely need to increase the accelerator pump discharge nozzles to .037 - .040 to solve this.

What is the intake centerline on that cam? Where did you get it?

 

Speedtigger, Thanks I will do exactly that, I value your input.
I have read your sticky at the top, I must admit I got lost at the beach for awhile though.
But that information is way above my paygrade. I am looking forward to learning how to tune a carb.
That is the GM stage 2 hot cam, part number 88958722.
https://sdparts.com/details/gm-perfo...parts/88958722
I looked for the intake centerline # but could not find, it did not have a card with the cam.
Is lobe centerline the same? it reads to be 108*

 

I would contact the original owner and find out if it was previously used for blow through or (draw through) roots supercharged. A lot of internal mods are made to deal with boost and I'm not sure they would be easy for a novice to reverse. Not trying to offend you. The roots style mods should be easy enough that just returning the carb to stock settings as suggested by speed would take care of it.

 

No offense taken, thats why I asked you guys.
I know if you want to learn something, talk with people who know what they are doing.

Thanks for that, that is something I did not know to ask the seller when I purchased. it's been over a year since purchase, don't know if i can find seller info, will check though.
Been gathering parts for awhile, and finally getting to the point to where I think I can
see the light, maybe it's just a reflection though.

 

Post a picture of the carb. Maybe it will be obvious. The mods made for blowthrough are here--->http://www.hangar18fabrication.com/blowthru.html maybe you can spot some of them.

 

I had a blow thru carb set up in my 67. I had a 750 with mods to support blow thru. My cam was about like yours. 550's on lift with 108 lobe center line. I had a p600b around 10lbs of boost. I would 60 ft in the 1.5s. Run high 10s on pump gas. The motor was 355 with old bow tie heads. They flowed about what a stock vortec heads does. The 108 cam was fun as hell. I was told i was running the wrong cam and it would pick up better by having a wider lobe. So i got a cam about the same sixe with a 112 lobe. It was lazy and my boost went up to 13 lbs. Slowed down almost a second. The 112 cam would of been a good turbo cam. If your going with a blower blow thru set keep your cam and rock on.

 

Sorry, Don't know how to put a regular picture on here.
Wanted to take the bowls off and look but didn't have time after work before job #2
Thanks for the time and links I appreciate it, I will try to read some of them tonight.

 

That carb is NOT a blow through design. It's not sealed and still has the choke. Like speed said just return it to stock settings according to the book and tune from there.

 

http://csucarbs.com/5-blow-through-750.html. You can send it to csu.

 

Hey thanks for taking your time stunningman that's good to know. Going to start hunting
the carb. parts now.

Rob, thats interesting to know about the cam and blower, and thanks for the carb. link,
I am pretty stubborn, I think I want to try and rebuild the carb. myself and maybe accidentally learn something. That will be fun to see the difference between your old
setup and the new ls, let us know what kind of difference you get.

 

I see speedtigger said refer to 4779 in that list for the holley kits, I noticed there is a
4779-9 down a page or 2 on that list should I go with the 4779 or 4779-9
my carb says 4779-9 on the choke tower.

 

If the choke tower says -9, then go with the -9 specs. As long as nobody has swapped out metering plates you, that'll get you back to spec.

 

Ok, thanks.

 

If this is a roots blower carb then it's probably not going to work right.
With a roots blower the carb is always seeing vacuum under the base of the carb so the power valve won't work correctly unless it modified. The typical modification involves drilling the metering block internally and plugging the base externally so the vacuum signal the power valve see's is rerouted to the side of the carb (typically where the distributor vacuum port).

 

Hey thanks for the heads up on that LLLosingit, next time I have some time I will remove the metering block and see if I can tel,l and post a pic.
I'm almost thinking if I have to get new metering block's and all the other stuff, I'll be close to a new carb price, looking at the quick fuel with the glass sight bowls. I think the
metering blocks will be the deciding factor. Thanks again everybody.