1978 Corvette L82 Engine Upgrades

Item Posts    Sort Order

1978 Corvette L82 Engine Upgrades

corpsfreak1018 corpsfreak1018
I watched Corvette Summer | Posts: 4 | Joined: 03/07
Posted: 03/02/07
04:38 PM

I just bought a 1978 Corvette L82 Silver Anniversary Edition. It comes stock with a 220hp enigne but i want to know if anyone knows about any enigne upgrades that i can purchase. thanks  

Thad_theImpaler Thad_theImpaler
Cross-Fire Crazy | Posts: 50 | Joined: 07/06
Posted: 03/03/07
03:21 PM

any engine upgrades for the L82 should be your standard fare Gen 1 350 upgrades.  Simple things are swapping out your exhaust manifolds for headers, swap out your intake manifold, change carbs, etc.  Depending on the condition of your engine, you may just want to have it rebuilt.  What you need to think about then is if you want to keep it numbers matching, or if you want to go beyond.  From what I understand you can have  your stock crank & rods reconditioned or replaced outright, you can overbore the cylinders, your pistons will probably need replaced regardless, replace your camshaft, and port the L82 heads, even turn it into a 383 and you'll still be within NCRS standards as long as everything outside the engine is 'stock' since they won't tear into your engine to verify every component.  If numbers don't matter to you at all, along with the above options you can replace your cylinder heads.  Aftermarket heads like the aluminum Corvette L98 heads, iron Vortec heads, and the GMPP Aluminum Fast-Burn heads are great.  There's also other aftermarket heads from places like Dart & Summit too.

Another common option is just to replace your engine outright.  Just pull your stock L82 and set it aside to keep it unmolested, and drop in a new crate engine or a custom engine built to your spec.  That way if you plan to sell the '78 somewhere down the road, you'll be able to command a higher price as you'll still have the original numbers-matching engine to sell with it, or restore it to factory spec yourself later if you feel like it.  It really all depends on what you want to do.  

55Guy 55Guy
Administrator | Posts: 210 | Joined: 07/06
Posted: 03/05/07
12:57 PM

first question ot ask yourself: Do I want to mess withthe original engine or go with a crate motor and build from there. As mentioned in the previous post, the original engine in stock form could have value later on. A drop in ZZ4 would work great in your car if you decide to go the crate motor route.

If you decide to play with te stock motor and the shortblock and roatating assembly is in good shape, I'd recommend a full top end replacement. New heads, cam, intake and carb will do your Vette good. Along with exhaust upgrades such as headers, low restriction cats and mufflers, your motor would run pretty good.  

Terry-#008 Terry-#008
I watched Corvette Summer | Posts: 15 | Joined: 03/07
Posted: 04/22/08
03:09 PM

Hi Guys,
 I recently purchased a 1978 L82 4 spd. The engine lopes and it sounds really cool. I'm the 4th owner as far as I can tell. There was an engine rebuilt according to the last owner, about 10,000 miles ago. I have restored the interior to like-new condition and have refurbished the entire engine compartment. And I have had a complete flowmaster true dual exhaust system installed with a cross over. I've done a lot of research and from what I can tell the entire clean air pacjkage has been removed including the air pump. I have just purchased an Edlebrock Performer RPM Air-Gap Intake Manifold and a Holley 650. I plan to install this and want to know if there is anyone here who is familiar with the hook ups I need to make for the engine vaccum system. I appreciate all the help you all have provided me with.


vneathery vneathery
I watched Corvette Summer | Posts: 1 | Joined: 04/08
Posted: 04/23/08
10:33 AM

Thad, you appear to know about numbers matching.  I am looking at a '78 and have the VIN. Do you know of a place I can go to look up the original engine block number?  I have tried some of the vin lookup sites, but they only go back to 1980 and won't accept my VIN.  

Thad_theImpaler Thad_theImpaler
Cross-Fire Crazy | Posts: 50 | Joined: 07/06
Posted: 05/01/08
01:08 AM

Google is your friend, however, you may want to pick this book up:


JonSmith84 JonSmith84
I watched Corvette Summer | Posts: 3 | Joined: 08/10
Posted: 08/01/10
12:37 AM

edlebrock intake manifold with a 650cfm carb does mine well on the original motor, got rid of some of the evap system. but im planning a swap-I got a vortec motor 5.7 for a low cost...-look at salvage in good condition-NO FRONT END ACCIDENTS or Motor problems. I am hoping to keep the original vette motor original so a swap is in my mind....the 5.7 will get a reburb-bearings, seals, gaskets, and a new cam and possibly roller rockers 1.6 to make that a more performance minded motor without doing all that to the origial engine. also a trans swap is what I plan to do. maybe something with a OD? why not? Grin  

JonSmith84 JonSmith84
I watched Corvette Summer | Posts: 3 | Joined: 08/10
Posted: 08/01/10
12:48 AM

there are plenty of ports for a vacuum hookup, I used a edl performer not RPM cause RPM rises higher and you may need a taller hood. a edl 600 or 650 performer carb is doing well on my 78 too. I also upgraded the distributor to a eccel and high power eccel coil and wires and replaced the plugs.-get it tuned and it will work well with a edbrock 360 intake filter. with the top end done go for some headers-i prefer shorties but whatever you like, just make sure it fits. and a ac adapter may be needed if you have ac. and a cruise conrol adaptor for the carb may be needed if you also have cruise control. I would also suggest true duel exaust. I use valvoline maxlife oil and a quart of lucas oil for cushioning for the motor.  

dtmiller dtmiller
I watched Corvette Summer | Posts: 1 | Joined: 03/12
Posted: 03/23/12
03:41 PM

i was wondering if you ever found a hood to fit over the edle
broc airgap intake? i have the same thing and i have been trying to find an aftermarket hood so i dont have to cut my original. any suggestions? thanks  

pepsi1 pepsi1
Duntov Incarnate | Posts: 88 | Joined: 01/12
Posted: 03/24/12
12:51 AM

OH YEAH! Find the specs for a 68 Z28 and when your done brother hold on............ But you need gears with this combination it likes the higher RPM range...........
If you can't find it let me know I'd be glad to help you......


87corvette 87corvette
Duntov Incarnate | Posts: 171 | Joined: 03/12
Posted: 04/10/12
12:11 AM

As far as aftermarket heads go, I love the AFR 195s!!  Just be sure your entire package works with everything.  Summit tech is great! (if you get the right person).  Chevy High Performance magazine also has one of the best tech Q and A sections I have ever read.  

87corvette 87corvette
Duntov Incarnate | Posts: 171 | Joined: 03/12
Posted: 04/10/12
12:12 AM

Also the Fast EFI is cool and tucks nicely under the stock air cleaner.  

RickTomballTx RickTomballTx
I watched Corvette Summer | Posts: 1 | Joined: 09/13
Posted: 09/23/13
04:47 PM

I have a 1978 Corvette ad it has a 350 and a Performer Edelbrock. I want to go to the Performer RPM and rebuild my engine for max power. It is the hood clearance I am worried about. Is there any issues or a different intake manifold for me to look at.

waynep712222 waynep712222
Cross-Fire Crazy | Posts: 35 | Joined: 04/13
Posted: 09/23/13
08:55 PM

there are several styles of aftermarket hoods available for 77 to 81 C3 models..

you have several options...

call around and find a used one..

search swap meets..

buy a new one and have a body shop paint to match your existing paint job.. many body and paint shops have color matching machines..  so they can get very close..

this way.. you can remove your OE hood and hang it carefully from its hinge mounting points on the wall.. in your shop.. in your garage.. in the living room..

laying it flat and unsupported or at an angle could warp it.

there is very limited room under a STOCK C3 hood for additional height of manifolds or air cleaners..

some of the catalogs post measurements from the top of the engine block to the carb mounting surface.. so you can judge how much clearance you need..

there are also a few DROP around the carb type of air cleaners.. but your car probably already has one of those...

time for a clay cone to accept the hood closing on it to check height..

think playdoh