New Guy 1st post: Street Car Engine Choice 5.3 vs 5.7 vs LS3

i agree with Doc. Low mileage f-body for $1500 is gonna be a unicorn.
You could probably find a "low mileage" 5.3 or 4.8 for that money depending on where you live and how long you feel like waiting.

FYI the reason I went with my trailblazer engine was that it was $1600 for a LS2 with truck accessories... but it sure as heck isn't low mileage and of course the accessories are wrong.

Yeah, if you're after low mileage you'll pay for it. I've been into enough modern engines with 150+k miles and still seen hone marks in the cylinder walls to bother with that concern too much. Modern oil is pretty amazing.

A couple things to consider:
Ls1 intake is junk. Whether you get an ls1 or a truck engine you'll want an ls6 intake. There is a seller on ebay with dozens of used ls6 intakes complete with returnless fuel rail and ls6 injectors for $400. He is in kuwait and shipping takes a while, but everything came in good shape and works great. So intake cost is a wash unless you buy an ls6.

Water pump. Yes a truck water pump is different, but chances are if you freshen up your engine you'll be buying a water pump anyways. So that's a wash.

A truck alternator will work with f body brackets.

So, if you are looking at $1000+ difference between ls1/6 engines and lq4/9 6.0 engines you may be better off with the truck engine. And chances are a truck or suv engine hasn't had the snot driven out of it like an f body or corvette.

Oh, and good deals can be found on car-part.com as well. Sounds like a generic site name but it has salvage yard listings that you arent going to find on craigslist and it will search in a radius of your zip code

I went with an aluminum block 5.3 truck engine (L33) which was a full drop out. I'm not sure how prices are in your area, but where I live the hotrod market has pushed pricing on all of the aluminum block engines, along with the large displacement iron blocks, up to the point where crate engines start to look attractive. I had been searching for about six months before finding my engine; while not ideal, it seemed to be a decent compromise between completeness, mileage and price. Below are the purchases I have made to "convert" my drop-in L33 to fit like a drop-in LS1/LS6 would.

My engine was full drop-out so included all the accessories, ecu, DBW pedal and control module, throttle body, wiring harness, and all the truck accessories. It was about $1,700 to my door. On top of that, I've purchased a flywheel (Fidanza) for about $300, a set of brand new CTS-V front end accessories for about $900 as a kit from gmpp, water pump and harmonic balancer, about another $200 combined. I also needed to purchase fuel rails and fittings to work with a car manifold (ebay, earls and speedway) for about $250, and for injectors to fit an LS1/LS6 style intake I purchased a used set of truck flex fuel injectors ($120). Finally I will be buying a new Doorman LS6 replacement manifold for about $300. Add in gaskets and other assorted odds and ends, and I will have spent between $3500 and $4000. While still less than a drop-out LS1/LS6 locally, I've basically doubled the cost of my bargain L33.

It is worth noting that figure only partially covers the typical refresh items like a new oil pump, timing chain, lifters, etc. And if you add in performance some parts to help cover horsepower gap between an LS1 and my L33, then the cost jumps up even more. I bought a cam, push rods, springs .. may have the heads ported .. probably another $1500 all in.

That pushes my L33 build to about $5000 for a used 5.3 liter engine with about the same HP as an LS6 with a mild cam.

Would I do it this way again? I think it would depend on the cost and availability of the alternatives. But it does take some of the bite out of the cost of a budget crate engine.

Thanks erioshi.

That's a pretty good run down, and while it sounds like you got a good setup, just how you like it, it does approach the crate pricing. Which is kinda what i'm finding, after Kent from TPC gave me a similar list of parts to what you spec'd out. It does add up.

So I guess I agree with these other comments about LS1's getting older, right now eBay's looking like $3500-$4500 for under 100k (and a lot over 100k too).

Which leads me to the other post I just started about a possible crate engine supplier.

Here are a couple more factors to consider. First how complete is the crate engine or used LS1/LS2/LS6 you are looking at? Those little bits that are not included can also drive costs up very very quickly. My drop-out included basically everything I will need except the MAF, starter (may have came with the engine, just not remembering it), f-body engine mounts, and some intake tubing. Had I asked, they probably would have included the MAF and starter, or made them low cost add-ons.

Second, unless you are getting a fully documented rebuild, even today's "low mileage" engine may come with close to 100k miles. I think my L33 was listed with about 70K miles on it. Not bad based on how long these engines seem to run, but enough miles to require a bit of a tear-down and inspection before putting into the car, unless you don't mind pulling engines. The newer engines around where I live also come at quite a premium.

Also, had I known more about LS based engines, I might have held out for a gen VI engine instead of going with a gen III. While there are not a lot of differences, the gen VI heads seem to have better flow and power potential than the gen III heads. I do believe some gen VI heads will cross to a gen III block, but there are limitations, and gotchas. Small bore engines like the 4.8 and 5.3 blocks (same bore size) would require heads from the same bore size gen IV. And of course using gen IV heads requires a gen IV compatible intake manifold. The gen IV intake manifold is designed to work with rectangular (vs cathedral) intake ports, and uses a different bolt pattern (and size, I think) for the throttle body. A lot of small details that would make building up a short block quite complicated.

I'm not sure if all gen IV heads are rectangular port, or just the ones on the larger engines. The cathedral port heads on my L33 may be able to flow enough air to meet my engine's needs, even with an aggressive cam. If not, my heads still might meet my needs with some CnC porting. I'm still trying to figure out my options and the trade-offs involved. Honestly that is why I haven't bought an intake manifold yet; I'm still trying to figure out my final plan for the heads, intake and throttle body. Of course if I swap to gen IV stuff, there will be added cost. Gen IV heads mean gen IV intake which means gen IV throttle body. And in my case that could also mean changing out the ECU, throttle pedal and pedal control module, along with the throttle body and DBW pedal and module. And an ECU change might also require different connectors, sensors, MAF, and possibly wiring changes. But not all of that may need to change .. more research...

Coming from the turbo import world, I knew having a proper head and cam set-up was important. In the LS world, there are a lot more options for both heads and cams, and it seems to be even more critical to make the right choices. Here we don't have a turbo to force air past poor parts selection and design choices.

I guess what I have learned is that when building an LS engine, start with displacement, then figure out the heads, then the cam, and finally the rest. I suppose it's not that different from building an engine from scratch in the import scene, but there do seem to be quite a few more ways to get lost if you're not careful.

I realize you are looking at crate engines; I basically added this info to give more depth to my first post. And it seems to be a bit more justification for possibly starting with a well thought out crate engine.

I think for my build, given all the possible follow on effects of changing heads, I'm going to look at CnC porting the gen III heads on my engine and call it a day. They are 799 castings, so one of the better flowing gen III head designs and not a bad place to start. The whole point of my drop-out was to minimize the potential for getting lost.

Another option is to have a motor built for you, there are many LS motor builders out there that can build anything you want.

I'm very happy with my Thompson Motorsports 383 stroker...

So not sure if this helps depending on where you live, but there's a kid in Dayton, OH that parts out F-bodies and sells the engines pretty cheap. I got a '99 LS1 from him with 70k miles and it included wiring harness, PCM and all the accessories for $2000.

Just search LS1 in auto parts on Craigslist Dayton, and you'll see his posts pop up from time to time. Sorry I can't think of a name at the moment, but I see his posts several times a year when I'm just surfing around.

Hope this helps.

Also just saw this today. LS6 for $3,500. They've had this ad up a few times, I bet $3k would take it. For the price of some LS1's this would be a much better platform to make some nutty/somewhat reliable hp for the track. Had one been around when I started my build I would have def. gone LS6. I've driven two cars with the LS6 in my time, and they are just bulldogs. You can beat on em all day.

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Yeah, the LS6 is cool. And I do appreciate all the input, but 130k is definitely not "low" mileage in my book.

I'm think after a few days of looking around and talking with people, I'm getting my heart set on going with a crate. And in general, I'm between two crates: 350hp 5.3L or 430 6.2L.

There's a bit of a price difference between the two, and as was mentioned here I need to figure out what exactly comes with each to get a good idea on the "true" price difference.

On one hand the LS3 will be stock and have a ton of room to get a lot more out of it years down the road. But on the other, as one of my priorities is reliability, I am a little nervous about over 400 hp/trq on my old car. So maybe starting out with 350hp/trq is a better base with less wear and tear on the rest of the car. And you can still get a bunch more out of the 5.3L in the future too.

That's really what I'm down to. Decisions. Decisions.

I wouldn't worry about too much power if this is a street car. Just be sensible with it and you will be fine. The power-band is so predictable that even with all the power its easy to drive. Also the 944 handles the extra power with no problem. Just no launches and remember to roll on the throttle if you want your transmission and CV's to last.

My LS1 is probably making similar power to a stock LS3. On 93oct it made 380whp which is pretty close to what most stock LS3's do. This is with a cam, long tubes, LS6 intake and ported throttle body. The car hauls ass but as long as you respect the power and have a reasonable amount of rubber on the back (275's on mine) it hooks fine. If your really trying though, you can spin the tires through 3rd gear .

I think your on the right track though. I looked around for a good LS donor for a friend of mine last year and was surprised at how limited the options were. The LS1, LS2 and LS6 are not as easy to find nowadays and most are asking what i think is crazy money for a used engine. If i were shopping for an engine again i would be looking at a crate LS3 or a 5.3L like you. Personally i would probably go with the LS3 because it would cost you a minimum of $1k to get the same power of a LS3 from the 5.3L if you factor in a cam and essential valve train upgrades. Starting out fresh with a brand new engine is also really nice!

Personally, instead of adding power later I'd try to get close to my target right out of the box. Since the single largest power increase will come from a combination of ported heads, new cam, and quite possibly upgraded valve springs, the cost of the upgrade might be a significant percentage of your original crate engine price. You would likely be money ahead spending even an extra $1,500 (depending on upgrades) to start with the extra power.

Crate depot 6663.oo US 480 hp ready to go. I bought my harness / contoller pedal etc GM parts direct. 950. If I remember. Just saying.

Thanks for all the replies. Especially those with personal experiences with similar power level.

Techno Duck, thanks for the thoughts about rolling on the power, etc. I have stayed away from trying to act cool with a burnout, when I cooked the original rubber clutch. And that was with the stock NA "power"! So I don't plan on beating on it. But I do appreciate your thoughts on the power, and your build sounds nice.

I do like the thought of hitting the goal right away. But I also know, after years of DE's and track days, there's always that point that you want a little more. And I mean, judging by the horsepower creep of the automotive market, Camry's and Accords will have 500hp 5 years from now. So I'll probably want to kick up the hp then too.

Even on the track i think 430bhp will last you a long time before you wanted to upgrade. My car, power wise is so far beyond my skill level i sometimes coast down the last 3/4 of the straights. . Mind you, 430bhp in a sub 3k lb car has a power to weight ratio equal to a 997TT.

Personally i would just go crate LS3, but its easy to spend other peoples money. If you just want to put it in the car and probably never touch it again the LS3 hotcam engine Kevin mentioned would be nice though i honestly cant imagine what my car would be like with another 100bhp, probably straight up dangerous haha.

The only thing i really am not crazy about with the LS3 is its drive by wire, maybe i'm just old school but i prefer the cable. My friend is using the LS3 hot cam in the swap he built and the pedal took some time to get hooked up. I forgot how much power his car made but i think it was close to 500bhp with a good tune. The guy who tuned it (same guy that initially tuned mine) said the GM factory tune is fairly conservative on that engine, so there is a lot of room for improvement.

The crate motor and controller are plug and play.They layout all the wiring very nicely. I will have to double check but mine is 6 wires and Half of them are grounds. I don't no what troubles techno ducks friend had with the accelorater pedal but it took me about an hour to install my pedal. In fact when you remove the stock pedal it's drill a few holes and it sits nice on the old pedal stop and into the start of the tunnel. I will take some pics. As techno duck stated the tune from factory very mild. When I was deciding on what cam to use. Mine was stock 430hp. I did a lot of reading on line about cam tests.
With all the different companies doing theses tests on the LS motors and specific on the 430 LS3 they did a base tune on the motor before starting to change out cams. Every article I read they were all able to put a good clean tune into the stock motor and achieve on average 485 hp to 493 hp. That's a lot of ponys just with a proper tune.in the end I did the gm hot cam. So according to gm that cam bumps me up to 480 hp stock. If you add what was gained in the initial tune you are around 530 hp. Now you add stainless long tube pipes. They say they add another 40 plus hp dinoed and I think they state more power in thee add but 40 on the safe side your now at 570 add à new intake 10 hp. You can see the math. Don't take my word but I did a lot of research about the engines and the key is let them breath. There are a lot of good articles on line that support what I mention. They were car craft hot rod etc. I am hopefully dropping mine on the dyno soon just engine to have it tuned and run in. I am very curious to see what it makes. As techno duck said you get 500 plus hp in these cars and scary fast. Mine is a 78 924 2640 lbs to start. Hope to be around 2500 when complete. Power to weight will be awesome.

In my experience doing math like that ends up with you being disappointed with the final result when you get it on the dyno and tested...

I am just saying. If what they say is half accurate you can produce some good reliable hp that will be daily driver friendly. For me if I have a solid 500 plus hp at the end of the day there will be zero dissapointment. My car was 110 hp from factory and was a lot of fun to drive. Add the new hp and I can't wait. But if you are by new crate mill for the money the 480 is a good buy.

My point is it's not accurate at all. You can't just add up HP claims and think you're going to have an eleventy billion HP engine...

Ya I understand that doc. But a base 430 or 480 stock is a good solid platform to start with. That's all I am saying.  The dyno will tell the truth at the end of the day.if you have the money in your budget you can't go wrong. Not trying to piss anybody off here but to get the stock power of a new LS3 versus beefing up an LS1 my money did go into the LS3.

Thanks all.

I have heard that the base 430 is underrated and there is room to tune. And I've also heard that the 480 cam is good, but not as mean as the 525 cam. And neither of those are as underrated. So the recommendation was go either 430 or 525. And since this will be a street car, I don't want it to sound like a beast or be too rough at idle. So if I end up going crate (which everyone is talking me into) I think it will most likely be LS3 crate.

If I'm gonna do it, might as well do it right.