Hey guys, David here, ex-Cali77l-82 and ex-Cali,68,L-79 from way back and I mean 2002. Anyway, I’m getting ready to retire and get back into the Corvette game. Never had a big block. Been eyeing a 68 or 69 big block convertible, but the other part of me has seen the main streaming of LS conversions. Couple hundred companies out there making wiring harness entire kits to mod the C3 to accept an LS conversion. I shined away from it for years because of all the hassle but now I know there’s plenty of them out there that I can buy already done. What I’m asking for is your real assessment of the pitfalls or the pluses and upfront I no longer care about matching numbers. I don’t care about originality. I already went down that road twice. This would be a driver that would get used regularly and flogged hard. Just some pictures from the past for any viewers out there to recognize who I am and upfront sorry for being gone for so long.(2008-now)



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And again, I’m not looking to do the work. I’m looking for a completed project or at least 90% complete. 100% VA disabled tear and there’s no more wrenching in my future. So I’m not gonna install an endless motor that’s out of the question.

 

My opinion, You need to decide exactly what you want and go find the car that’s built the way you want it.
There are plenty of LS converted cars out on the market and plenty of more original big block cars for sale.
Either way, if you want it complete with top quality components and work, be prepared to pay the price.
I like big block old school power and when I open the hood, I don’t want to see a modern LS in the engine compartment.
They just look wrong in there, just like modern wheels on classic cars.
You LS guys don’t take offense, I like what I like and the OP asked!

 

yeah, I agree. There’s something about a big block that I just love the look and the sound. But of course on the other side there’s the argument that the LS blocks make more horsepower then the big blocks and their 125-175lbs. lighter and handle better….of course fuel economy issue (5.49 for 91 Octane). I mean it’s no contest. I think I was at best getting maybe 14 miles a gallon in the 68 and that’s only a 327.🤦🏻🤦🏻

 

I'm a LS guy. Done 10? LS swaps into various vehicles over the years. Both 5/6speeds and 4L60E.
I get my ECM's and engine wiring harnesses from Speartech or Howell. They need all the details of your engine trans combo. At the least you will need drive tune to dial in your combo in.
I like the build.
Pics.

 

I personally wouldn't go searching out an old car if I didn't have the ability to wrench on it. Not because I love wrenching (I don't, despite how much time I spend doing it), but because it gets real expensive real fast taking an old car that will inevitably have issues to a shop for every little thing that comes up. That goes especially for a heavily modified car to which there is no factory repair manual for them to work from.

But, since you've been down this road before, I'm guess you know what you're getting into on that front. The pitfalls come down to one thing: how good the installer was. Lots of little things have to be done right for an EFI setup to run right. Lots of things have to be accounted for to make an LS fit and interface with everything it needs to. Did they hack up the harness? Did they run the harness in areas where it can burn or chafe? Do they have sensor wires running next to ignition wires? Do they have a reliable setup for the fuel pump and pressure regulator? Are the driveline angles correct? Are the radiator fans properly shrouded? Are the radiator fans strong enough to keep up on a hot day in traffic? What ECU did they choose and how was it tuned?

Its harder to screw up a carbureted setup than it is an EFI setup. If I were buying someone else's project, it'd have to be a VERY clean install for me to consider an LS. And I'd be looking in detail at everything I could possibly access. Less pitfalls with a carb, but once either one is set up and tuned properly, they'll both do what you want.

 

Welcome back

Having had a 327, 350, a balanced/blueprinted 468 Big Block ( dynoed 638hp) and now a mildly modded all aluminum LS/T56 6Speed... only thing I miss the the look and sound of the Big Block. Besides that, I love all the attributes of the LS with modern tech and truly a "get in and go" car, and 20mpg+ is nice. All of the previous engines were reliable but the LS is less finicky; the BB would get on the warm side in heavy traffic and would want to load up at times w/ the 850DP. I can say I have zero regrets on making the swap.

 

So the pics below will make some chuckle. The 67 Nova SS that I bought from a guy that had engaged a so called LS swap expert. 2002 LS1/4l60E. Was a totally rust free CA car. The previous owner got totally hosed by the LS swap expert. The previous owner put it on CL. I contacted him. Made him an offer and he took it.
Changed it up to a sleeved and stroked LS2 to 427 cubes. The sleeving done by RED in Ca.
The thing about LS swaps on older (40-50) year old cars is typically the stock wiring harnesses are junk. Need to replace them completely IMO.
Then because I'm not any kind of wiring guy I buy a LS ECM engine trans harness and chassis harness from a known supplier. Good grounds can not be over stated.
I've done all my LS swaps myself. I like the build.
The 98 Wrangler has a LS6/4L60E swap. Has been totally bullet proof for over 16 years. Plowing snow tomorrow. It's -5 degrees and with a 35 mph NW wind. Nice to have heat and defrost along with a hot cup of in the console.

 

The most exciting Corvette-related thing that happened to me in December was finding not one, but two LS4 engines to use for my 73 shell (the VIN indicates it was originally an LS4 big block). One LS4 even came inside a complete, running car! I already have a 5-speed manual that should work, and I can salvage the old chassis from my 79.

Did I mention these are Gen IV LS4s, with 243 heads (the same casting as the heads on a C5 Z06)?

I wouldn't ever consider running a Gen 1 SBC, or any flavor of big block, when it is so easy to get more HP from an LS (or Gen V LT) than the C3's drivetrain can handle.

If I couldn't build one myself, I'd buy one from Bring a Trailer.
https://bringatrailer.com/chevrolet/...upe-1968-1972/

 

Here’s an LS powered 1972 that’s been for sale on here for almost two years. Looks like a really nice car, I’m surprised it hasn’t sold yet.

 

both beautiful builds!! it’s funny you added it in the 67? C-10 because I’ve been looking at those as well. Back to the C-3 is that a Griffin aluminum radiator? That’s a really nice install. I noticed you used the stock brakes and was just wondering why you didn’t upgrade to who won the new modern Hydro boost or other breaking system she would see on the mid 2000s GM products that have a much smaller surface area because you don’t need the large brake booster(supplied by the power steering pump). Not that the stock system isn’t good enough. You can see on mine. I went from manual to power brakes.

 

that’s exactly right there what I’m talking about! Back in the day, my friends in the San Diego Corvette owners Association always talked about overheating issues with the big block C2-C3’s. And that’s even with going full bore with one pusher and two puller fans… really really nice man!

 

yeah, I’m kind of partial to a convertible but that’s a hell of a deal down to 47,000!!

 

So I'm kind of a rut in regards to C5 brakes on my hotrods excluding the 71 C3. It had totally rebuilt C3 brakes with a new booster and master. The LS1 was totally stock so tons of vacuum for the booster.
On the front of the 68 C10 I used ZO6 14" front rotors with C5 calipers. 12" 2002 Camaro rear discs. 2004 C5 booster and 2002 Camaro master. The LS6 had a small cam so vacuum was not a issue.
On the 67 Nova I had help from Tobin at Kore3.com to spec out the manual master size. They worked very well just had push a bit harder compared to power brakes.
I did a 66 Mustang with C5 brakes all around. 306 small block//T5 combo with a pretty big cam. On that hot rod I used a hydro boost. It would put your nose up against glass. IIRC from Hydratech.com?
So having said the above if can't do the work yourself I would really consider a late model of some type. My current project is a 80 Camaro with a LS3/4L60E swap. I'm the second owner. Bought it from the son after the dad passed away. 28K original miles no hit car. Not one speck of rust. I did a subframe off resto. Drives great.
But and there is always a but. It doesn't drive nearly as nice as our 20 Mustang 5.0 GT vert. We consider the 20 Mustang our long distance hot rod.

 

Amazing rides, fantastic work!!

 

Thanks for the kind words.
I like the build. For me the build was a stress reliever. Out working in the shop I never thought about work. My wife of 46 years was very cool with me out in the shop working on my latest hot rod.
Pic of my latest 80 Camaro project.
I build them. Drive them a few years and then something else catches my eye. Sell them to fund the next project.
By the way I'm looking for a really clean Chev 1500 OBS short box for a new project. No rust. No crash damage. Clean title. Engine doesn't matter. Cash in hand.

 

I don’t know how you find time for all that that’s for almost concourse level cars. I still haven’t retired yet but when I get home after a long workday, the best I can ever hope for is spending 20 minutes in the garage just barely enough time to clean a windshield or vacuum the interior and I’m done for the day I’m hoping that turns about with my soon retirement plans that’s why I’m kind of holding out because I don’t wanna buy yet another car that sits and never gets to love I wanna take it too because I just simply don’t have the time.

 

I’ve been retired for three years now.
I find myself doing everything that needs to be done around the house, yard work, running errands, spending time with my wife and hiking with our pups.
When there is nothing left I can find to do I’ll go out into the garage for some time to work on the car.
An hour or two a day at the most.
From Spring to Fall we spend time camping, hiking and exploring for weeks at a time.
When you retire, you might find you have less time to do things like working on a car because you get to enjoy so many other things that you didn’t have time to enjoy before retirement.

 

One thing I had was some really good advice years ago. Buy the best car you can afford. No rust no hit cars. Yes they aren't cheap but they are going to save you a bunch of money in the long run.
If you don't have the skills to inspect a car prior to purchase find someone who can.

 

Oh and hiking the next week or so is out of the question. West central MN -25 tomorrow night air temp. We have two labs and they don't spend much time outside taking a leak.