454’s Dying – LS / turbo Swap It or Stay Old School?

[GaryKr]

My Z28’s 454 is about toast (2–3 PSI hot idle oil pressure). So its Time to rebuild… or ditch it for an LS.


Plan A: What I was thinking when I traded for the Peanut port 454 was rebuilding to my RIP Grandfathers old School Ls7.
All forged 12.5:1 on E85. Sounded badass, but when discussing my grandma straight up told me my grandpa’s old LS7 454 was nothing but trouble and got 6 MPG on race fuel. Shops want $2–3k in machine work, plus $3k-5k in parts easy.


Plan B: My brother works at a scrap yard. I can get a free LS + 4L80E. LQ4/LQ9 or 5.3 aluminum? No problem. Sometimes a 6.2 shows up. T56 would be sick, but rare as hell. Cam it, turbo it, 600–800 HP with decent MPG. Hard to hate that.


I love rowing gears (current Muncie setup), but hard to beat free power.


What would you do? Let’s see pics of your builds!

My wife also wants me to add AC....anyone got any Vintage Air equipped turbo LS engine bay photos you care to share?

Also - If you have gone from a Built 454 to an LS...do you regret it?

Photo for attention....

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As long as its not your daily driver, Big Block all the way! LS set up is more reliable BUT you can't beat the flat torque curve. If this was actually your GP even better . Put in a roller cam

 

['70 Z/28 RS]

I can't go anywhere without someone saying to me... "Put a big block in it!" or "Put an LS in it!" Nah, not gonna.

 

[biker]

I like what biker said. Your 454 is free too. It’s not cracked or blown we think? You might give it a refresh . Clean up the bores , new rings. New crankshaft bearing etc. when I look at the LS motor , I see an ugly alien laying there , just just a mess of 100 parts, tubes , hoses ,runners , wires . The clean old school engines are a thing of beauty. At a show I just admire the cars , pay no attention to LS motors . So if I was diving it to work , using it everyday, then some sort of new motor will hold up better ,you might think. As biker said , there will be more involved than meets the eye , as you are changing everything. If you drag race every weekend , use the LS. The 454 can give you old school CHEAP thrills , without out all the direct port, super high compression, turbos , electronic crap or Computers. I think you might be amazed how a few days at the beauty shop might wake up your tired old 454. Some of them in 70’s would easy run 300,000 in a Chevy suburban , the blocks are very thick and strong. Tear it down , see if it worth fixing ?

Simple is SO good. All of this "LS is more reliable" is poop. A basic small or big block is every bit as reliable, maybe more so. Set up the distributor and carb properly and enjoy.
OR...gasp!...pop an intake and carb setup on the LS...at least it's up and running and you can plan and save for an EFI setup down the road. May find it isnt needed.

 

[Bentley]

Simple is SO good. All of this "LS is more reliable" is poop. A basic small or big block is every bit as reliable, maybe more so. Set up the distributor and carb properly and enjoy.
OR...gasp!...pop an intake and carb setup on the LS...at least it's up and running and you can plan and save for an EFI setup down the road. May find it isnt needed.

there is kit made to convert your LS to a distibutor also ....

 

[my24ktrat]

...Ahh ,don't forget about the deep tone a big block makes with cubes. There is no ls or small block that sounds like it, I myself ,have an LS6 454 GM crate engine , a 400 sbc, and a 350 , just my .02, DC.

 

[Gamma454]

I will never go back a old school sbc or bbc. I would swap all day every day! 450 hp with just a cam 370 to the ground torque all day with. 89000 mile motor. It was a learning curve for sure. But i love the fact i can do old school and new. With all the rain my car has been sitting for 3 weeks and i can reach through the window and start it without pumping the gas or warming it up. No oil leaks. Modern AC all day . 24mpg on hwy , overdrive.
But if you’re not willing to learn sensors, and can wire really well. Stick to what you got.

 

[biker]

I will never go back a old school sbc or bbc. I would swap all day every day! 450 hp with just a cam 370 to the ground torque all day with. 89000 mile motor. It was a learning curve for sure. But i love the fact i can do old school and new. With all the rain my car has been sitting for 3 weeks and i can reach through the window and start it without pumping the gas or warming it up. No oil leaks. Modern AC all day . 24mpg on hwy , overdrive.
But if you’re not willing to learn sensors, and can wire really well. Stick to what you got.

Yes, once you get one under your belt and "see behind the curtain", you have the next one beat. Sounds like a nice setup.

 

[Icepick23]

You can him and haw at this forever...it's all about what your willing to do after you install it. Old school engines=chasing oil leaks, timing, fuel issues and lots of weekend tinkering and so on, which is fine if that's what you desire. LS=set it and pretty much forget it, it just runs and runs for the most part. Been building engines for around 40 yrs now and it's nice to not have to mess with stuff just to keep it up and running. Reliability with the LS is the game changer. I have confidence I can drive my LS anywhere long distance or inner city driving in hot weather, without a sweat.
I literally just got done building a 447 ( bored and stroked 390 ) with all the goodies installed and dyno to 490 hp and 550 ish torque. Built with all the best of the best parts and the machining to boot. We are now chasing small oil leaks, fuel issues along with heat related issues. Just constant messing with things. It really comes down to what you're will to put up with AFTER the install and figure if it's worth your investment.

 

[Icepick23]

Simple is SO good. All of this "LS is more reliable" is poop.

Ha, I can a smell an old school engine miles away, let alone see the blue smoke coming from the exhaust. The "poop" is in the pudding

 

[1970camaroRS]

Gosh, this post made me return from the dead. If its a daily driver, 5.3 aluminum with a small cam and a 7875 turbo and a 4l80e. If its just for fun, keep the big block and throw a pair of 7875s on it blowing through a carb. Or a big t6 with 1.32 exhaust AR. Im currently building a Nova with a 488/8.0l tall deck, huge solid roller, electric power steering, electric power brakes and electric AC. Dry sump. TKO 6 speed. And a 88/103 single through a carb. Should be silly fun.

My last build was a bored and stroked lq4 4l80e twin 7875s in a 78 Cutlass made 874 at the tire through a stalled 4l80e. I've done N/A LS daily drivers, a 70 Camaro and a 78 Cutlass, carbed and Efi. I did a 454 with a miniblower in the Camaro once. And a procharged 355 blow through. So, I've dailyed a bunch of oddball combos. Best one was the N/A 6.0l with a medium sized cam and a stalled 4l80e. Ran 10.99 and got decent mileage on premium gas.