Gooood morning!

So I've got a 1979 Vette and it is an absolute slug. When I bought it I was under the impression that it had the original 350 in it, come to find out it actually has an earlier 350 (from around 74 in it). Either way it does not have a lot of get up and go. Any suggestions to get some more horses out of it? Eventually (when my current engine goes) I am planning on throwing a ZZ4 in it. So I dont want to throw a boat load of cash into tuning this one up. I'd like to stay at or below a couple hundred.

Additionally - I like the idea of side pipes and headers.. If i were to buy them now and put them on this chevy 350 from ~74ish do you all think they would match up on a ZZ4 or would I have to buy different headers?

 

The truth about mods and horsepower and torque:

FAST aint cheap

Cheap aint fast

How much power you get is an exponential function of $$ spent



Now: gears in the rear end can make a huge difference in de-slugging the car what gear is in your car 3.08?

Side pipes are way cool I have them They are not cheap and even buying used and refurb is expensive

also check local emission's laws or you could get into the doo doo with the po po

thumbnail: to deslug the car requires $$ save up and do it right

 

stock L48's from the mid to late 70's weren't powerhouses, they were the 4bbl truck engine you got in the C10's. my L48 with headers/sidepipes made a whopping 197hp at the wheels, out of breath at about 4500rpm. and with a TH350 with 3.08 out back it wasent turning quick times at the track.

 

Yessir, to my knowledge it still has the 3.08s in the rear end.

As far as "Fast Aint Cheap" like I said in the post, I am going put a ZZ4 in when this engine goes along with a new tranny and w/e else I decide to get into when that day comes. In the mean time it would be great to get a little more thrill out of driving! I dont know alot about this car (yet) and was hoping that someone could point me in the right direction. If there’s nothing that can be done to an older 350 to get a little more pick me up then so be it, but if there is I am open to suggestions!

Side pipe questions: Where did you purchase your side pipes? What headers are you using? Are there different "baffle" options that could still meet stringent emission reulations?

@1977L48 - that sounds about right, I dont feel like I am getting anything over 200 out of mine.

 

Recurve ur dizzy, it makes a huge difference, cheap upgrade and gives you a great seat of the pants feel of more hp, also czech all vacuum lines for leaks, do a basic tune up, plugs, wires, cap, rotor, mine would do a brake stand with just side pipes, mine are the hooker headers side pipes and were on when i got my vette

 

Hi Boon88,

A couple hundred is not going to get you much from the performance department.

You could look at getting your distributor re-curved and maybe a tune-up.

The limited funds are not going to allow you to build performance into the existing engine.

With regards to side pipes and headers. The side pipes will work on either your 350 or the ZZ4, but the headers for your engine versus the ZZ4 will be slightly different due to the different exhaust port configuration of the heads.

You might be able to make them work but I've never physically tried so I can't say 100%.

Hope that helps.

 

Why don't you skip the ZZ4 and rebuild the 350 you have into a stroker engine? You could get a lot of hp/ tq out of that engine with a proper rebuild. You could ditch the smog equipment and add the headers/ sidepipes now, since you would need to do that with a good engine anyways. If it's registered "Historic" you probably don't need to worry about emission inspections.

 

on a 1979 there is no legal way to run side pipes if your state has emission's laws In Florida I just do it and nobody cares

I would put a gear in the car, you start getting into cams and the like and knowing you are going to swap motors you are just wasting money.

I would swap gears and wait till you can afford a new motor

 

that is what mine did after recurved dizzy, side pipes, edelbrock intake with stock q-jet, and weiand alu water pump. I was dragging the brakes the entire time and left the th350 in 1st. running 10 degrees timing, 160 t stat. it had 205hp at the wheels at that time

 

Wow lots of good feedback, please excuse my ignorance with the following questions!

@donyue - what will recurving a distributer do? I did a quick google search/forum check and I'm still not entirely sure what it does or how to do it?

@MIKE80 - I recently drove one of my buddies 79's with a 383 in it. It was pretty incredible. I have reservations about turning a 39year old engine into a power house like that. That’s why I was leaning towards the ZZ4. I could buy it brand new and get a lot of life out of it... Then eventually when it went I could turn it into a stroker and know that it is not older than I am! What kind of reliability/longevity would you expect to get out of an old 350 to 383 rebuild?

And to anyone else, what gear would you all suggest? I had 3.73s in a 03 mustang back in the day and I was a huge fan. But I have read alot of complaints with anything that low for C3s on this forum. Mostly this is our (my wife and I) weekend car. But we do occasionally take it to events/gatherings. So I would like to be able to take highway trips as well as burn around town.

 

Hi Boon88,

Re-curving the distributor basically adjusts the setup to work best for your engine in a performance application with the fuel that you have available to you.

The factory curve of the distributor was made for best fuel economy/emissions and not necessarily best performance.

The proper re-curve process requires some specialized testing equipment that the average person doesn't have available to them.

It's best to see if there are any race shops in your near-by vicinity that can do this work for you if you have not done it before.

With regards to differential gears, I would chose a 3.55 or something similar.

I have 3.70s in mine and it makes for good performance around town but on the highway the engine runs around 3000 RPM at 60 MPH.

That engine RPM does not make if very fuel efficient.

For me I will be changing my 4 speed to a 5 speed in the future so I will leave the rear gears alone as 5th will drop the engine RPMS to about 2000 RPM or lower.

If my car was an automatic and I was not going to change the transmission then I would drop my rear end gears to 3.55 or even a little lower for better highway cruising. JMHO.

 

I felt the same way too, when I got my car.
Now, after doing the things mentioned by 1977L48 and donyue, I have additionally had the stock heads off for a rebuild(at 110,000 mi.) and am satisfied with the way it runs. It will not burn up the track and set records but that's not how I drive. I consider it a good cruiser with enough pep to get out of it's own way. 3:55 gears and now a 200-4r trans.
Good luck with yours.

 

if you can find a set of big valve 882's (IE L82 882's) and have a valve job done on them, gasket match the intake runners and have them milled it will give you alittle, I have a set sitting here at the house that need a new intake valve due to valve spring breaking.

 

First off, you need to be certain that your Q-Jet secondaries are actually opening. If they are not, you are trying to 'feed' your engine with those little primary 2-barrel venturi. Not gonna go fast that way.

When a Q-Jet fully opens, the engine will have a much louder, deep, throaty sound that is unmistakable from any other carb. If you aren't hearing that, the carb isn't even opening.

That could be because the floor mat is too thick....or because the throttle cable is not adjusted correctly....or because the secondary lockout link on the right-side of the carb baseplate is not allowing the secondary throttle plates to open, etc., etc.

Before you start throwing money around for "go faster" parts, you should make sure that your engine can actually make use of them.

Check/fix the throttle "system" to assure that the secondaries are fully opening WHEN THE ACCELERATOR PEDAL IS PUSHED TO THE FLOOR. Opening them with your hand on the carb linkage is NOT proof that your foot will do the same thing. So check and fix that stuff. Then, recurve your distributor and set timing for 'performance' (rather then lowest emissions and lowest warranty costs). Give the ignition a good tune up and adjust the carb correctly.

Now, put the 'pedal to the metal' and see how that feels. If you've done your job well, it will give you a good "kick in the pants"....'70s 350 or not. And, if that's not enough for you, THEN you can go throw money at your 'go faster' parts.

 

I 2nd what 7T1vette said, you wouldn't imagine the hp the secondary's make when opened, I first discovered this while working on an 84 Monte Carlo SS with a 305ho, it wouldn't get out of its own way, and I loosened the top butterfly's and the secondary's opened and WOW, when I purchased my vette same thing with it, loosened the screws and adjusted the plates so it would open, and it made a huge difference

 

1977L48 describes the secondary airvalve adjustment. This *may* be an issue, but likely if the carb is old the secondary spring has worn out has decreased the preload on the airvalve doors anyways.

Some people make the mistake of loosening these up so much that the doors open too early and cause a bog. If you can *feel* the secondaries kicking in, your airvalves are too loose.

As for 7T1Vette's post, it's very good advice. I'd just like to add the following:
1) the primary throttle linkage is controlled by the throttle cable, verify that hits 100%.
2) The secondary throttle linkage is controlled by the primary throttle linkage. It should begin opening at ~2/3 of the primary throttle travel. Some early and pretty much all late model QJets (M4Ms) use a spring actuated secondary. This allows the lockout that 7T1 mentioned to function. If the secondaries have sat for a while, they may not rotate under the pressure of the secondary spring. That said, you should check them for full travel as 7T1 said and if they do not have it (and the primary does), try lubing the secondary shaft with your lubricant of choice. The last QuadraJet I built had the secondaries seized solid, but a couple shots of CLP (my go-to gun lube) freed them up.

 

There is no reason you can't use your original block to build a 383. I'm using my 77 two bolt main block in my 383. I've put about 200 1/4 mile passes on it. Ran 12.44 two weeks ago.

 

for 2 hundred bucks all you can afford to do is the carb and dist... Do those. You will be suprised how much fun you will get from just having it run correctly. The carb that is on her is a good one and will really come to life, if it is set up correctly. Then when you are ready, pull the motor and take it to your buddies friend at the machine shop and have them "stroke" it. 383 is a whole lot of fun, and it will still be a numbers matching car, mostly...

 

Hm... Roughly how much do you think it would cost to stroke the current motor to 383? Making me rethink the ZZ4 idea. Sure seems like it may be quite a bit cheaper to stoke out my current 350. If I were to have the current 350 stoked what other upgrades would I need to make to keep her from falling apart? Thanks for the interesting ideas. Keep them comming!

 

You can get a cast crank for $200. That and a set of pistons, I have forged but you could use hypereutectics, maybe $300, bore and hone the block, use your stock rods add a flat tappet cam and you have a 383 short block that could put you in the 12s.