Hey guys I just purchased this car last week. It was a barn find that had been in a family since new. The owner tried to start it about 3 years ago but was unable to keep it running for a long period of time due to apparently it having the wrong carb on it. It's a Rochester but from a different car. I purchased a new Edelbrock 1406 that will be here tomorrow. But my main questions are where the heck do all these vacuum lines go to. I have studied several diagrams but can't seem to figure out where they all go. Some of them I know but would like an expert option before I just go hooking hoses up. He told me that a mechanic unhooked several of the hoses to try and get the car to run right but never hooked them back up after figuring out its the wrong carb. The car does have an edelbrock intake and headers on it already. It has been sitting for 20+yrs and I am picking up new brakes, calipers, rotors, plugs, wires, fuel filter, oil, oil filter, antifreeze and brake fluids. There is very little gas in the tank from what I can see so I will siphon what I can out and add new fuel to it. So if you can please look at the pictures I would like to have some hel on where the vacuum hoses go. Also this new carb is electric choke. How does that get hooked up? In one pic there is what appears to be a cable of some sort with a cap/threaded cap on it and I have no clue where it goes.

 

pic 1, does anything get hooked there?
pic 2, where does this go? It's a pretty big tube but I don't see anything it can hook too.
pic 3, is the cable I was talking about.
pic 4 and pic 5, vacuum hoses.

I see on my stat housing there are two barb fittings, I know where the hoses go for that, they have plugs in them and I can hook them back up.
Thanks

 

You should be able to find pictures of '74 350 engines on the forum that would help you identify various components.

 

#5 is PCV hose, goes right onto the part stuck into valve cover by your hand.

#4 is the headlight vacuum filter (white) and connects to the hose with bolt in end next to your valve cover Chevy hold-down bolt. Other end of that hose is probably going to the double nipple manifold connector in background.

#3 looks like speedometer cable, if so should connect to side transmission. You'll need to check about that or have someone else confirm and advise. Updated: Alan 71 got it, of course! Tach cable.... Well now, that wouldn't have occurred to me.

#2 went to air cleaner (99% sure).

#1 linkage arm... missing... connects secondaries to choke, upper slide slot. A short arm is on the lower slot already.

 

Hi K,
Welcome!
It sounds like you have your work cut out for you!
But a 74 Corvette! Nice!!!
This is a 71 but may be a bit of help to you.
Do you know about the 74 Assembly Instruction Manual and the 74 Chassis Service Manual? They will be a big help to you and are available from the larger Corvette vendors for not too much $$.
Regards,
Alan

1. Linkage rod missing as LRH suggests. (This is a Rochester Q-Jet in the picture.)


2. Again agree with LHR. Crankcase breather connects to air cleaner base. 'Similar' to this 71 air cleaner


3. Tachometer cable connects to side of distributor at its base.


4. Vacuum supply for headlight operation. Fitting in intake manifold to the rear of the carb.


5. PVC hose connection.

 

Thank you guys so much, I am hopefully going to tackle some of these issues this afternoon. I will post verification pictures when I am done.

Alan, that engine and engine compartment is pristine!

 

Ok, so one issue so far. The tachometer cable in pic 3, I can't get it in. The inlet for it is facing the firewall?? I can't turn the cable enough to get it in the hole.

 

That's an easy fix!
Just turn the distributor so the cable goes straight in.
Here's a how-to:

 

Alan's entire car looks like that!

 

Just in case you are not aware, unless you have a dual pattern manifold, you are going to need a spread bore to square bore adapter to use that carb.

 

This might be of help to you, go to Edelbrocks web site and watch their videos on carb installation and set up. good luck with your project.

 

Hmm, ok thanks, I think the guy just put a regular edelbrock instake on there. I have the box for the new intake as it has the original one in it. Ill check it out.

One other question, Looking at Peterbuilts picture. If I move the distributor won't that effect my timing? I see where it says to move the wire over one spot but is there anyway to do this without lifting up the distributor and risking throwing the timing all out of wack? I am 34 now and the last time I had messed with a SBC that was carburated was when I was 16-18. "84 IROC." I am a little rusty and I just want to get this bad boy to at least run and idle.

 

Congrats on the 74... I bought one myself 4 years ago (when I was 34) and its finally coming together.

Chances are the timing will have to be readjusted anyway... honestly its not installed correctly anyway since the tack cable connection is facing the wrong way... you will want to get a timing gun. now might be a good time to check the points too and maybe switch to something like a pertronix point replacement module.

You can rebuild the carb thats on it with the correct jets/tuning and it should work fine from what I know of Qjet carbs.

something to keep in mind on the 74, it has a number of one year only features, if it hasnt been disabled there are sensors under the seats which will not allow the car to start unless your seatbelt is fastened and your in the driver seat. You can hit the rubber button on the aluminum box located on the top passenger firewall to temporarily bypass this if I remember right.. I disabled mine. if you search here you will find more info on it.

Its also the last year vette that you can LEGALLY put sidepipes on due to not having cat converters!

 

I am just not familiar with how to use a timing light. I am fully capable of doing all this stuff myself, have all the tools to do so just need to find a video/tutorial on how to do this so I don't mess anything up.

 

I didnt know either until I bought a vw kitcar... In fact I knew very little about car engines when I bought my vette but it didnt stop me from doing a lot of reading on forums and watching a lot of youtube videos and being able to build my own replacement engine for the 74 from scratch. There are a lot of youtube videos on setting the timing on a SBC

I use a $12 harbor freight timing gun .. you will be messing and tweaking the timing a few times once the rest of the engine is in order so...

 

I liked this one.

 

Hi Kevin,
This post explains about timing.
https://www.corvetteforum.com/forums...long-post.html

Email Lars at
v8fastcars@msn.com
and ask for
'How to set your timing for peak performance' and
'How to install your Chevy distributor'.

Send him your picture of the carbs missing rod and ask if he has one for you.

Pete.

 

I'd stick with the Quadrajet. It's fine for a stock motor and you'll get better mileage.

P.S. When you get your calipers, get the stainless steel sleeves with O rings.

 

Good to hear. Got one over a year ago, MG TD replica, and its timing was way off. Didn't know anything about those old VW's, have learned a lot since then.

Don't know if anyone has mentioned yet about the harmonic balancer, which the timing mark is on. Mine doesn't show up using a timing light on it, apparently either slipped or installed wrong when water pump (and who knows what else) was replaced.

Just thought I would say this in case yours doesn't show where expected either. You'll either need to create a new mark on the HB after confirming TDC or get it fixed if so.

 

I will be looking at this once I install all my brake parts that I just picked up yesterday. Rear bumper just arrived too and front bumper should arrive this week. I can already tell the rear is going to be a huge PITA!!! I have fiberglass stuck in my fingers from trying to remove the rusted bumper tab nuts. Only have 3 more to remove then the rest of whats left of the bumper will come off.