Would you do it? Rip out a Turbo LS for a Big Block

[americanmusc1e]

I'm in the middle of a mini "restoration". The C10 currently has a junkyard turbo LS setup in it. The engine is ugly and old but the thing makes stupid power. Most of the time I have it turned down to 9-10 PSI which is still ~500whp.

Got a while hair. Put my turbo setup and engine on facebook marketplace to trade for a Big Block Chevy. I've got a few offers. All are pretty stock Gen V or Gen VI motors.

Big Block:
- I'd be stepping down in power. By nearly half. Kinda okay with that. You can make a ton of power with a big block chevy but it's expensive.
- Would definitely be going carbureted. I'm very okay with that and i miss not having a truck with a carburetor.
- I could simplify the engine bay a LOT. Big Blocks just look cool.

Turbo LS:
- this thing is peak performance for this chassis. The performance is downright scary. I can hit 120mph passing someone before I realize it.
- it sounds GOOD.
- it's ugly. mine is especially ugly.
- I have almost 4 years of dialing this setup in. It needs nothing to be functional. I'm bored at this point because the only direction is more power and this chassis doesn't need it.

Am I insane for wanting to change?

[HO455]

Originally Posted by americanmusc1e

Am I insane for wanting to change?

Not at all.

Personally I’ve always enjoyed driving vehicles with stock looking engines that run far harder than anyone expects them to. Other than being asked to leave because the car doesn't have a roll bar it's great. And today there is this thinking that people believe that only LS cars are fast. Those people can't believe their eyes when they look under the hood, so they immediately start looking for the nitrous system.

Then there is that feeling of violently accelerating that you don't get with a modern EFI engine. For me that is worth every dollar spent.

[Rust_never_sleeps]

If you want that look, then yes.
That other mill provides more power when you want it and more mileage when you don't, so there's no logical reason not to leave it there(and pretty it up perhaps), but this doesn't have to be a logical decision, it's a hobby

[RustyPile]

My '71 has a mild 454 in it.. It will melt holes into the asphalt if I ask it to.. I love everything about it except it doesn't know how to pass up a gas pump. I wouldn't even consider trading it for one of those LS thingies...

[jocko]

let me think... big block vs hair dryer. I know what my answer is

[57taskforce]

I’d keep the turbo LS… you’ve already got the time and money into making it run good.. leave it alone and let it eat. It’s gonna cost you a lot to get similar numbers out of a bbc and the big block is quite a bit heavier, which throws the front to rear balance even further off… Just my opinion. I like big blocks, I’ve got a few of them. But with what you’ve already got, I’d focus on cleaning the engine bay up and enjoying it.

[LS short box]

My question is why not pretty up the LS/turbo swap? Pretty easy to clean up the wiring and turbo inlet and outlet tubing. I'm not running a turbo but you can make the wiring go away with careful routing. My 68 LS6/T56 swap pic.
You didn't say what tranny you are running. Would that need mods for the big block.
I can't see adding a 250 lb plus more than the LS iron big block/heads engine to the nose of the truck for a bunch less horse power. Less rear traction due to the added front end weight?

[weq92f]

.

An OEM cover for you LS, some cleaning, paint and those covers that would hide plumbing and cooler there in front of the radiator would go a long way to fixing up the engine bay.

-klb

[ghackett1]

Let me think about this for a second — YES

['68OrangeSunshine]

I'd dump an LS just on GP. Hate 'em. DKY except they're period incorrect. To me it's like putting an SBC in a vintage Jaguar.
Also computers hate me.
I had a 454 in a '67 K/10 Suburban. It was fun at 80, the whole doghouse shook like a GoGo Dancer with white boots. It had a 735 CFM Carter AFB. Intake and exhaust were stock cast iron. Truck passed anything on the road, but a hi test gas pump.

[mkmc69]

My 2 cents. Keep that truck as is and have fun with it. Buy another truck and build a nice driver big block for it. I realize that is alot of money spent, but you can't take it with you......

[Joyridin]

I dumped the big block for an LT. Not exactly the same as yours, but the BBC was an overweight behemoth that did nothing but suck a lot of gas and give mediocre hp numbers.

Clean up the engine bay a bit on the engine you have. I am guessing you have an OD transmission, so you should be getting some decent mileage.

The BBC is a slug unless you do a bunch of modifications to make it put out some power, but then you are getting 6-10 mpg on premium. If your truck is a show truck, then maybe that is the way to go. For a driver though, the LS has it in every way, shape, and form.

[i82much]

I am a dyed-in-the-wool old car guy. I like old cars and trucks that look, sound, smell, and run like old cars. I like manual chokes and messing with distributors and turning idle screws and changing accelerator pump cams. I kind of even like buzzing down the freeway at 3000 rpm and nervously watching my water pump gauge on a hot day.

All that being said, i find that i spend way too much time working on my old junk and not enough time actually driving it. So for me, once i get it running good, i dont mess with it for awhile. I would rather drive an old truck with the "wrong" engine then spend all my time wrenching to get the "right" engine going.

[3drburb]

No, I would not rip that out. If you are bored with Turbo LS that is dialed in with all the power and maybe decent gas mileage, I would bet you would be bored with the big block as soon as you get it installed and driving. You most likely love to build stuff and just need another challenge.
Btw, I would love to have that turbo Ls, I guess I should be looking for a nice big block to trade. LOL

[americanmusc1e]

Well I did it!

Thank you all for the comments. I love the wide range of replies and it shows that we are a diverse group of truck guys. I see a couple of common themes:

1. Dont mess with a good thing. To that i say "I'm gonna" I've had the C10 since I was 16 and it's what I test out new ideas on. I've had a 350, built 383, LS w/od, Turbo LS and now it's time to try out a big block. I guess if I hate it I'll sell it and build a new LS setup.

2. Fuel economy. I know the big block is going to be bad, but my turbo LS with a TH400 and 3.08 gears only does about 10mpg on premium. i've never seen more than 12mpg with this truck. Even with a stockish 5.3 and a 5speed. If you drive 60mph or below you could probably do better but the speed limits in tx are 75mph or more on the highway. I'm not going 60

3. You can make a LS pretty. Kinda. Most people put various covers and things to hide the wires. In the end it's just not really my jam.

4. A mild 454 does make less power. I could build the 6.0 short block I have sitting here and dollar for dollar destroy a 454 in power numbers up to about 600hp N/A. To be honest. I'm trying to dial the power back. Those of you that think you want 500hp to the wheels in a 50 year old truck don't know what you are asking for. I've done some things. hit some speeds on accident that you just shouldn't go in an old truck. I literally passed a guy on the highway going 60 in a 70. I fully stomped it and by the time the truck spooled up and I was going around him I was doing 120. Driving a slow car fast is more fun than driving a fast car slow.


In the end, I'm in my 30s. I've never owned a big block chevy. Not really any of my friends have a big block chevy. I work with computers for my job. I've mastered EFI, but I like tinkering with simple mechanical things. I'm the one giving carburetor advice to my friends and I don't own a carbureted engine. Maybe I'll find that the old stuff isn't as great as I remember, but maybe I don't care. In the end, I'm not trying to change anyone's mind. I was just trying to justify it to myself. and I did.

[Ironangel]

I was going to say what the others said, clean up what you got and enjoy it! Meanwhile, get that big block on a stand and start gathering parts. I had a 69 L34 396 in one of my 72's and wasted the block when a valve let go. I took a 454 truck block and bored it .060" over and stuck the 396 forged crank in it with factory rods and JE forged domes. I used the 69 290 closed chamber iron heads, a solid Clay Smith cam and Howards EDM lifters. Comp Magnum rods and roller rockers. A radical 12.5:1 punched out and balanced 427 screamer that maybe makes 600hp @ 6K rpm. Cant afford to drive it with 110 octane going for $17 per gallon! It's alot of fun but barely streetable... First pic is the 396, second pic is the 427 (439ci)

[D.B]

It all depends on what you want from your truck. I like the old school motors and BBC just look awesome. Since my 72 was a factory big block I kept it that way and wanted it to look as factory as possible. As for power, if its done right you can have fun and enjoy it. Mine has a built 511 CID with Eagle crank and H-Beam rods, Edelbrock Perf RPM heads, Edelbrock Perf RPM Airgap intake, CC Roller Tip rockers and Crane Roller cam. It also has a built T400 trans, 2200rpm stall and a Gear Vendors OD. Factory Dana 60 with a Yukon Locker and 4.10 gears. Its not monster numbers but it does have right at 600hp at 5200rpm and 700 tq at 4200rpm. I also run AC here in Texas when its hot and the motor never gets over 180. Just got to make sure you do the cooling right. I like the LS plat form and they do make power. But in my opinion they just dont look as good as an old school BBC.

[MARKDTN]

More money and work for half the power (your words) and less fuel economy just to look cool and be period correct? No thanks. Keep what you have and spend the time and effort to make it look nicer or do suspension work to get the power to the ground IMHO. If the purists don't like it, close the hood. I cringe when I see a Hemi in a Chevy but an LS is a Chevy. I see no point in going backwards on power just to have a carburetor to fiddle with. My .02

[lolcopter]

After spending a lot of money building a big block to make it era correct, I should have went LS. The big block low end torque is nice but in a light truck just spins tires. I've also broken 3 built transmissions.

A turbo LS should be better on fuel when your out of boost. I get 10mpg on a good day with ethanol free.

Ultimately I like the big block but there is no way I'd pull out a turbo LS for it.

Reliability wise I would say they are similar.

[americanmusc1e]

Old engine came out! and new engine acquired.

It's a pretty much stock Gen VI 454. No fuel pump boss and factory roller cam.

[Willowrun]

The logical choice was to stay LS if this is your daily driver, but I'm assuming this is a toy so by all means big block. No better sound and feel than a big block under load at 5+ grand. Very distinct. And then you open the hood and see the fat valve covers. That won't ever go out of style.

Great choice and interested in seeing what you do with the Rat.

[MARKDTN]

Originally Posted by Willowrun

...No better sound and feel than a big block under load at 5+ grand. Very distinct....

Have you ever been behind a Cadillac CTSV that has been tuned a little? I'll put that sound right up there with a BB.

[americanmusc1e]

Originally Posted by MARKDTN

Have you ever been behind a Cadillac CTSV that has been tuned a little? I'll put that sound right up there with a BB.

A V8 with the only mufflers being a turbo and a little 8" glasspack through a 3.5" single exhaust sounds pretty wicked. I will miss that sound


a few old clips for your ears:

https://www.youtube.com/watch?v=7JIiMx_di8U

https://www.youtube.com/shorts/YRHnpgsiHXY

https://www.youtube.com/shorts/0PPhQjUAyQQ

[Yamariv]

Originally Posted by americanmusc1e

Old engine came out! and new engine acquired.

It's a pretty much stock Gen VI 454. No fuel pump boss and factory roller cam.

Good call, please keep us posted on the BBC install!

[57taskforce]

Originally Posted by MARKDTN

Have you ever been behind a Cadillac CTSV that has been tuned a little? I'll put that sound right up there with a BB.

That’s No joke, a cammed, boosted LS is a wicked sounding monster. I’ve almost got all the parts rounded up for my LSA swap in the 5th gen. I still woulda kept LS in this particular truck but I’m in to see what happens with the big block for sure.