I've decided to upgrade my 79 vette.
I'm getting my quad carb done by a local guy who loves upgrading them tomorrow!
My engine is sadly an l48 my tranny is an auto. I want to WAKE this thing up. Ill email engine photos to anyone who wants it. Here's the thing I'm assuming its an l48 and I'm not sure stock or upgraded. My exhaust was redone two months ago and isn't true dual no local place would figure out a way to do true dual. This will be my last thread for a while, I will however post pictures after my upgrades that have been going on a week and will prob take another week are finished. I'm on a couple grand budget max let me know what to do please. Won't be able to make serious cash to put into car until may. So please be note that low price cap when throwing out the ideas please

 

I'm thinking of adding a true dual exhaust to my 79. Thinking about using the system from Corvette Central with the shorty headers.

 

Do true dual it will take some part replacements but I regret not doing true dual

 

A 3.42 rear gear would wake your 79 up!

 

79 L48 auto came with a 3.55. Is that still in the car? It's actually a good all-around gear ratio.

Also - You have a new exhaust, does that include headers? You can wake the car up just with a good timing and carb tune with headers before you go any deeper.

If that is already done, then a moderate heads/intake/cam swap could be done for around $2K. But I would make sure the timing and carb are in good shape before you spend any money on other engine parts.

Depends on how much you want to WAKE it up.

 

The exhaust didnt include new headers. Just sent my carb off by a local professional. And I want it to wake up BIG time

 

You can't wake it up "big time" with a $2000 budget. An upgrade vortec kit from Scoggins Dickey $1100 and a comp XE 262 cam K Kit $400 with a set of headers and true dual exhaust all dialed in will get you a substantial improvement for close to your budget.

 

63Mako is right - My 1st "project" was very similar to what he describes above - It was a pretty noticeable improvement. Main difference was I went with the roller version of the 262 cam - it turned my beat-up L48 into a nice fun driver.

So not sure if you can save enough back to buy the retro roller kit vs flat-tappet, but it's worth it IMO.

 

If you can go roller it will help with performance and no wiped cam lobes.

 

Low end Torque is the key to a fun street car.
INTAKE:
The stock intake sucks, find a good aftermarket dual plane like a edlebrock performer or equivalent with a spread bore pattern so the Q-jet will work. Watch hood clearance and don't get something too tall to fit under the hood.
CARB:
A basically stock Q-JET is an excellent carb for street/strip use. Don't let anyone tell you different. Most folks go with a Holly or Edelbrock because everyone else does. There were used on everything from 4.3 liter V-6's to 500 CU Caddy engines. ONLY two sizes were ever produced, 750 CFM and a few rare 800 CFM used on some HO big block engines. They are vacuum operated and only allow the maximum air/fuel flow or CFM the engine is capable of using. Biggest complaint is secondary "Bog" because the air flap is not properly adjusted and a simple fix.
CAMSHAFT:
Easiest way to wake an engine up. Look for something around 260° duration and 450 lift. A split pattern profile with more exhaust duration can really help cylinder scavenging on an engine with stock heads or poor flowing exhaust. Don't "Over Cam" the engine especially on the intake duration side. Too much duration moves the torque band way above idle and causes poor manifold vacuum that power brakes don't like and an idle quality a stock torque converter can't handle if you are running a auto. Anything over 470 lift is pushing it with stock springs. Big cams sound great but are pigs without at least 10:1 compression and low gears.
EXHAUST: Stock manifolds are restrictive. Add a quality set of headers and free flowing exhaust. Don't skimp with a low quality set or you will have fitment problems and constantly replacing gaskets from crappy flanges. Run the biggest exhaust pipe you can run behind the collector and free flowing mufflers. This can be done and the car still relatively quite.
IGNITION:
Often overlooked but a big power maker... The goal is to get all the MECHANICAL advance timing in at around 3000 RPM's, usually around 34 to 38 degrees. Run all the timing you can without detonation or pre-ignition at wide open throttle. A stock HEI will work, but you will have to do some spring work on the mechanical advance.
VACUUM advance is critical for off idle and part throttle cruise performance. After the mechanical advance is set without any vacuum advance, hook the distributor vacuum to a manifold vacuum source, not ported. Via an adjustable vacuum advance on the dizzy, run all the part throttle or criuse advance you can with out pre ignition. 50 degrees or more is not uncommon. A small block Chevy loves advance at cruise and idle. Time the engine where its happy, not the factory spec of 8° BTDC of what ever is recommend.
For $150 bucks or less you can buy a new Accel or MSD HEI dizzy with a performance module, new cap and rotor and an adjustable vacuum advance cheaper than you can modify the stock one.

Of course these mods are for a "healthy" engine that is not down on compression or has high miles. The goal is to make all the TORQUE you can from idle to 5000 RPM's for a fun street car.

 

I stroked my engine out to a 383 for under $2000... it was a BIG wake up to my L48.

 

If you want to wake up the car - put a 700R into it. 1st gear on the tranny will leave you breathless. 1st gear on the TH350 is bloody crap.

 

Listen to 63mako-he knows what he is talking about….

As for gearing and transmission swaps, those are really band aids to an underpowered engine-185 Stock Net Hp is 185 HP…. Headers, Timing, and duals with no cat can get you an additional 30-40 HP at the rear wheels over the stock exhaust system.