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LS3 ? or SBC

28K views 126 replies 32 participants last post by  Larger Dave  
#1 ·
LS3 … or SBC

I’ve been thinking about an LS3 swap for at least a couple years, started a thread, looking to come up with a parts list, etc. I have a 68 with a 350 74-78 truck motor, TKO600 w/ 3.73, complete global west suspension, and Unisteer rack & pinion. Runs pretty well, no real problems.

The more I learn about the swap, the more i realize what a huge project it is (motor, electronics, mounts, headers, radiator, gas tank, etc, etc). From time to time I think it would we so much more simple to get a nice warmed over 350, 383, 400 sbc. I’m just looking for a little more hp and torque (and has to look nice). Other factor is, I can’t see doing the project myself (as much as I’d love to!), due to conflicting priorities for time, owning/running a business, family, etc. I thought I had someone lined up to do the LS3 swap for me this spring, until he blew me off (after waiting a year already).

For what it’s worth, I’d appreciate everyone’s feedback and advice (please). LS3 or SBC, and why? Thanx for listening.

Brad
 
#6 ·
Re: LS3 … or SBC

it is easy to get 5-600 hp out of a sb without all the head aches of going ls
LS is easy and not near the headache of a 500 plus HP SBC and much more reliable

Either way power cost $.
 
#7 ·
Re: LS3 … or SBC

I’ve been thinking about an LS3 swap for at least a couple years, started a thread, looking to come up with a parts list, etc. I have a 68 with a 350 74-78 truck motor, TKO600 w/ 3.73, complete global west suspension, and Unisteer rack & pinion. Runs pretty well, no real problems.

The more I learn about the swap, the more i realize what a huge project it is (motor, electronics, mounts, headers, radiator, gas tank, etc, etc). From time to time I think it would we so much more simple to get a nice warmed over 350, 383, 400 sbc. I’m just looking for a little more hp and torque (and has to look nice). Other factor is, I can’t see doing the project myself (as much as I’d love to!), due to conflicting priorities for time, owning/running a business, family, etc. I thought I had someone lined up to do the LS3 swap for me this spring, until he blew me off (after waiting a year already).

For what it’s worth, I’d appreciate everyone’s feedback and advice (please). LS3 or SBC, and why? Thanx for listening.

Brad
Just have John do the swap. He can do it in a week! He is the LS swap King!
 
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#10 ·
Re: LS3 … or SBC

You can get a ECU right from GM that works with the crate engine you buy. Never had mine hooked to a PC, no tuning was required. Entire car was plug and play except for tach and speedo output. All the Holley mounts and headers where spot on. Only fabrication I did was to mount a GTO radiator.

OP - Once you drive an old car with a fuel injected LS you be wondering why it took you so long to do it.
 
#11 ·
Re: LS3 … or SBC

Dave, if you were gonna build a hybrid LS would you choose Mitchells version over Darts? I am leaning Johns way towards a big crate having thought about the World Products block but the latest Dart version tempts me more.
 
#12 ·
Re: LS3 … or SBC

Awesome thread so far!! No bashing going on!! I really like the way you have yours set up Doug. I have seen Brent's as well kind of mix between old school and new school. I am old school but the addition of the EFI does add extra piece of mind and adds just enough "more" torque to the old school engine. I could imagine what the LS has to offer set up the same way.

I am not opposed to the LS. I just like the old school build of a SB or a BB Chevy.

My opinion if your leaning to the LS, the way Doug and others have done with a carb and intake set up would be my choice.
 
#13 ·
Re: LS3 … or SBC

Bill Mitchell was the first to market. To be truthful I wasn't even aware of Dart's offering.

I saw this build on my Sunday morning car show, andeven though it isn't a budget build it probably costs about the same as an LS-x swap; with the advantage of all of the SBC short block parts being readily available. A 440 cube SBC breathing through late model LS heads topped with a carburetor (my favorite since I see no reason to jump on the EFI band wagon just yet) made sense to me.

I haven't compared the costs of the build but I will wager it is close to the price of a Shafiroff standard deck 582 (I built one just like it and spent twice as much on parts) that you could paint orange and put 396 325 horse decals on (not that I would do that; I claimed my 582 was a 305 SBC with a three quarter race cam, and burnt out glass packs) Which is why having a flat hood and retaining the inner fenders is important. If any one noticed it was a BBC I claimed it was a 402 out of a one ton truck to explain the cam sound.

582 Big Block Chevy Ultrastreet Pump Gas Engine

Big Dave
 
#54 ·
Re: LS3 … or SBC

Bill Mitchell was the first to market. To be truthful I wasn't even aware of Dart's offering.

I saw this build on my Sunday morning car show, andeven though it isn't a budget build it probably costs about the same as an LS-x swap; with the advantage of all of the SBC short block parts being readily available. A 440 cube SBC breathing through late model LS heads topped with a carburetor (my favorite since I see no reason to jump on the EFI band wagon just yet) made sense to me.

I haven't compared the costs of the build but I will wager it is close to the price of a Shafiroff standard deck 582 (I built one just like it and spent twice as much on parts) that you could paint orange and put 396 325 horse decals on (not that I would do that; I claimed my 582 was a 305 SBC with a three quarter race cam, and burnt out glass packs) Which is why having a flat hood and retaining the inner fenders is important. If any one noticed it was a BBC I claimed it was a 402 out of a one ton truck to explain the cam sound.

582 Big Block Chevy Ultrastreet Pump Gas Engine

Big Dave
Not a savvy LS guy but what "type" heads were those in that segment Dave? I saw they were trick flow but what type heads? I know the world block they used require a return passage to the water pump? Were they LS3 heads or no? I am looking at pricing and doing a little research on heads for a build like they did.
 
#14 ·
Re: LS3 … or SBC

When I researched the Hybrid the cost was at least 50% to the cost of an LS GM crates motor all said and done.

Now if you have an SBC and can use a lot of the parts then the hybrid might be a good way to go.

They do make big power.
 
#15 · (Edited)
Re: LS3 … or SBC

Does anyone have links to these kits complete? What I mean is I'm aware of the Holley kits, but is there a complete kit bolt in for 1st Gen that comes with the crate engine too? or are there too many HP choices that make it hard to put the whole shebang together for one price?
Big Dave, that is a great price for that much horsepower!

Brett.....
 
#16 ·
Re: LS3 … or SBC

Does anyone have links to these kits complete? What I mean is I'm aware of the Holley kits, but is there a complete kit bolt in for 1st Gen that comes with the crate engine too? or are there too many HP choices that make it hard to put the whole shebang together for one price?
Big Dave, that is a great price for that much horsepower!

Brett.....
You can buy the Holley kit for the install and GM for the long block.


I'm sure there is someone who makes and sells a complete one stop shop kit.....but at a cost since all the legwork is done.
 
#18 ·
Re: LS3 … or SBC

I have come to believe that John is correct that the big crate LS is the best bang for the buck, and likely the best shot at a however reasonable long haul driver. But, if ya just gotta tinker, as i understand it, you cant bore the aluminum blocks but they are better strokers @ 4” than cast. You can bore cast however. Mitchells block has really only Erson (also Mitchell) as a cam source and the valve train geometry is weird. All thats left is the SHP LS Next from Dart. I dunno. I think it would be fun to have a “stump the observer” setup. I like the look of Dougs but also wouldnt object to losing the carb. I keep trolling for a deal on build parts but i will likely wind up with a crate.
 
#19 ·
Re: LS3 … or SBC

John, (I’m in MA) if I was closer to you…I’d drop it off next weekend! I was looking at the 480 as part of my LS3 swap plan. No idea what I have for hp right now. I feel like I’d be pretty happy in the 400-450+ hp range? I’m now thinking that if I go the sbc route, I can get the hp and tourque I’m looking for (yes?) without rattling my teeth at a stoplight, not spend quite as much $$(?), and it’s a pretty simple motor swap. What am I missing? Driving maybe 1500-2000 miles a year, the gas mileage benefit doesn’t make my socks go up and down.

Thanx for,everyone’s input!
 
#20 ·
Re: LS3 … or SBC

My LS3 is 525-550 HP smooth as silk and gets over 20 mpg cruising with the TKO600 and 3:73s

I really like old school too
I am as happy as a pig in mud:grin2: we figure my 383 is now 540 at the crank. originally 532 off the dyno. 26" tire, 3:55 rear and the gear vendor, running 75-(80 2600 rpm)mph freeway speed for a hour I got 17.174 mpg
 
#21 ·

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#23 ·
#22 ·
Re: LS3 … or SBC

Comparing the LS3 to a Gen 1 SBC, it's about a 75 to 100 hp advantage to the LS3.

The LS3 cylinder heads are amazing and only cost about $1400 ?

I found a LQ4 shortblock and LS3 heads for $2000 and am going with a carbed version.

I figure it's around 480 hp with the small "hot cam" from GM.
 
#24 · (Edited)
Re: LS3 … or SBC

Comparing the LS3 to a Gen 1 SBC, it's about a 75 to 100 hp advantage to the LS3.

The LS3 cylinder heads are amazing and only cost about $1400 ?

I found a LQ4 shortblock and LS3 heads for $2000 and am going with a carbed version.

I figure it's around 480 hp with the small "hot cam" from GM.

Basically same as my build but I used a much bigger cam. AKA: LY6 clone ;)
Mine has already evolved some, and cleaner looking now....never was happy with the top hose :sad:

Watch the intake valves (huge @ 2.165 and flow around 315cfm) …with only a hot cam and all else stock, you should be fine (BUT CHECK ANYWAY) your PTV clearance.
With the mods done on mine, I had to fly-cut the pistons for clearance.
 
#29 · (Edited)
#31 ·
#30 ·
Re: LS3 … or SBC

The LS3 480 rated 495 hp is only $300 more than the 430 hp. Very good for the extra $. Then add the controller for $1250 and a Holley front drive. I just installed the new mid mount on my LS3/525.
 
#33 ·
Re: LS3 … or SBC

With my TKO600 and 3.73s, someone tell me why I’m crazy to lean old school and just go with a sbc? What’s a reasonable amount of hp I could expect? If I go with a sbc, would you recommend a custom build from a very reputable engine builder locally (and let him pick the components he’s comfortable with), or just buy a turnkey motor from …?? How much should I except to spend?
 
#37 ·
Re: LS3 … or SBC

With my TKO600 and 3.73s, someone tell me why I’m crazy to lean old school and just go with a sbc? What’s a reasonable amount of hp I could expect? If I go with a sbc, would you recommend a custom build from a very reputable engine builder locally (and let him pick the components he’s comfortable with), or just buy a turnkey motor from …?? How much should I except to spend?
Just copy (or buy) this old-school crate engine; 435 hp with a 220/230 cam.

SP383 Crate Engine 425 HP Deluxe 19355722
 
#36 ·
Re: LS3 … or SBC

I for one do not think your crazy. You already have the sbc set up in the car. Ok the ls is a superior engine can't argue with that, but what are you looking for? The ls is lighter and gets better mpg's.
How much hp are you looking for? Want decent mileage(both can be had ls or sbc)?
With so many people swapping out perfectly running small blocks to join the bandwagon and go ls there are lots of great motors to choose from for a bargain.
I like old school, if you started with a shell and wanted pro touring go ls, I personally would by a Vette and make all the protouring old school cars look stupid.
When I grew up these cars were straight line performers that handled "ok".
Mine has a better anti sway bar then stock, handles a little better then stock but I aint
interested in 1g around turns. Mine is a Procharged bb so front end weight is against me besides I have fat soft wall drag radials out back.
Do what you want it's your car, a nice 427 small block with or without a blower can put a grin on your face that won't go away for a long time.
I know John will jump in and sing the praises of the ls but John build 50k plus cars kudos to him, and his customers.
If you are talking with a reliable engine builder then just tell him what you want and ask for the cost.
Like I said though plenty of sbc bargains out there. Go efi if you like efi vs carb.
 
#41 ·
Re: LS3 … or SBC

The LS engines are nice. I had one in my truck and my son has a couple of them. For me, in our old cars I prefer the good old SBC. Holley makes complete fuel injection kits, including the fuel system for a very reasonable price. This is for engines making up to 650HP.

And I enjoy spanking LS powered cars at the track. :grin2:
 

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owns 1969 Chevrolet Camaro
#42 ·
Re: LS3 … or SBC

John / anyone, how do,I get an idea as to what the idle would be like in a given engine (such as the one you recommended)? 2nd question, how much vacuum at idle (to run power brakes) do I need (12” sound right), and I don’t see any specs for that in the overview / specs in jegs or blueprint.

My apologies to everyone if I get the DUMB QUESTION of the day award here. I don’t even feel like I know what I don’t know, trying to find my way.
 
#43 ·
Re: LS3 … or SBC

No doubt, both "can be" built to a certain level of HP/TQ.

My old SBC 406ci solid roller 25X/26X @ .050 cam went 11.30 @ 119 and was a bit of a handful on the street in traffic to hit some cruise-ins...NOW with a 364" 23X/24X SBE (LS) and much tamer street manners went 10.96 @ 121. (so far)
Less cubic inches, smaller cam, SR Vs HR, I'm happy with my choice.

Personally, I would look for a local builder with a good reputation, and been in business for a few decades...or go new. Now use caution if you go "new" as some companies require you to use an ASE certified mechanic/shop for warranty to be valid ;)

READ THE FINE PRINT.