Id appreciate any advice, suggestions, sticky guidance (titles), or equivalent.

im getting closer to pulling the trigger on my first Ls based platform for a swap into my 07 GPW S2000.
coming from stock to a Scienceofspeed twin scroll setup on the 4cyl F22c1 making 435whp and 300wtq was awesome and it had great street driving behavior with full boost (12psi) by 3k--->8k redline!. I ended up getting the bug tho! selling it and getting a fullblown motorsports kit (T4 single scroll) making it even more high strung with 490/343. it was a runner! 15psi coming on full sung by late 5.5k tho. After getting comfy with it though, I felt the want of the torquier low end fun streeting feel back. Fast forward to a loss in compression on cyl4 and a memory of what I wanted to move back torwards. led me to the LS swap.

Parameters:
NA
LSx
aluminum block
fbody T56

I might be asking for my cake and the ability to eat it to (my tuner once told me this lol. When I said I loved my SOS kit but wanted to hang with the open scroll guys at the top of fifth) although I have long grew away from this Im afraid of, and reason why Im here Is I dont want to have to mod a ls1 to the hilt of it being a pain to tune, lose its feel down low, letting the gm reliability magic out lol,etc etc.

my goal is 430-435whp and 300wtq. Current rear diff is stock with iirc a 4.77FD but will at some point make it a puddymod diff with a 3.90FD??

Location: Kansas, Iirc around the 1100' msl.

so what platform should I start off with. That will require the least amount of mods to reach my goal?
and advice on, will the higher displacement engines carrying the higher price tags outweigh a smaller one with more mods?

I would really rather not settle for anything under 400, but I would settle if it was all said and done with 420+. This is not a rush and am taking my time to have exactly what Im looking for. I have considered an ls6 just because it seems to carry a track car behavior "persona" if you will from what I read. Plz dont quote me, but this is also a characteristic that I wouldnt want to ruin that the S2k stewie baths in.

Thanks in advance!

 

Whatever you get will be a win/win for you, you will love the usable powerband you get from a larger displaced V8 (right off idle all the way to redline).
You can look into an LS1, LS6, the 5.3L LS versions or maybe you can find a deal on an LS2. An LS3 would be great of course too but I doubt you can find a cheap enough one, but it will need the least amount of work for the power you want(just a small cam swap and you are there).
Either way 430rwhp is a total walk in the park with all of the above and you can have oem like reliability and beat the hell out of the engine and it will just ask for more. Also by default you will be making way way more than 300ft.lbs of torque, a bone stock LS1 makes 320+rwtq from the factory.
With an LS6 or LS2 all you would need is a decent sized cam and the supporting mods like valve springs and hardened pushrods and possibly injectors, these have better flowing heads than the LS1 so you don't "need" those. Or if you want it a little more tame/street friendly then add a good set of heads and use a smaller cam and you will still make 430+rwhp/400+ft.lbs with a flatter torque curve and better street manners.
LS1 and 5.3L version will need heads/cam just like above to reach 430+rwhp.
You shouldn't have to touch the crank, rods or pistons for that power level.

Here is an example of a custom cam on an LS6 that made 430rwhp and drives/feels like stock:
https://ls1tech.com/forums/dynamomet...k-results.html

Browse the dyno result section if you want to look at numbers for different setups:
https://ls1tech.com/forums/dynamomet...omparisons-65/

Keep into consideration that autos will have a ~20% drivetrain loss compared to the manuals ~15%.

 

Thanks. Sounds encouraging; I figured the trq inheritently would not be the problem, and I dont think Im asking a whole lot for the hp as well.

Just wanted to clarify im not missing something. Seems my research has me squared away. I feel the ls2 would mimick the strong flat trq curve I liked about the twin scroll, but like you said its really a win/win. Maybe the fact that I want to reach my goal with least amount of mods will have more weight in my selection.
Thanks again.

 

Forget N/A. Aluminum 5.3 with boost lol.

 

Any advice or big obstacles to mating an ls2 to a gto T56? Also the directions are specifically for the fbody camaro ls1/T56 combo. In my reading I dont even think "I have to" but it does sit an 1"-2" further back, but I also saw you can swap it out for fbody stuff (shifter "area"). So I think this is the simplest way to "achieve" a trans box with the triple cone synchros and not move away from "swap" headaches and ease of staying within the directions / tried and true.

Thanks! Have a merry xmas!

 

All of the Gen 3 (and technically Gen 4) engines are the same externally with a few minor exceptions. So if an LS1 will work, so will a 4.8 or 7.0. The main difference being the early 6.0s (1999) had a .400" longer crankshaft as did some of the 4.8s that same year. This means virtually any LS based engine will bolt right up to a T56 as if it were an LS1. Even the exceptions like the early long crankshaft truck engines and the LSA engine with its unique flexplate/flywheel bolt pattern can be used with the right flywheel.

The iron blocks are not drilled for the low mount alternator bracket, but you can easily drill out the block there yourself. The aluminum truck engines, even the 5.3 are already drilled here and the F-body alternator bracket will bolt right up. Basically, any combination of accessories can be used on any block. All of the exhaust and intake manifolds interchange for a given intake port (rectangle or cathedral). Heads interchange, cams, oil pans, mounts, etc.

So don't think you are limited specifically to an LS1.

I still stand by my recommendation of aluminum 5.3 and boost.

 

Lol, thanks for ALL of the advice including your 2nd recommendation on boost lol. I appreciate it, im done with boost for a while. I have had a boosted 4cyl for the last around 3yrs from 420ish-490whp. Never broke the magic 500! Lol but thats another story. I even drove across the country and then back to Kansas all boosted, but im done with the maintenance, dynoing etcetc for a while.

 

Get the LS2/T56 setup in there and you'll be wanting for boost soon enough. Luckily, blowers bolt right to the heads and running no hood is en vogue at the moment.

Also, LS2s are the most common aluminum engine out there. Camaros, Corvettes, TBSS, Saab 97x Aero, CTS-Vs, SSR, all had one at some point.

 

Eek lol, not as a daily.

 

Keep it simple. http://www.chevrolet.com/performance...ines/ls376-480

All factory. 495HP @ 6200 473 lb-ft @ 5000 Plenty of bottom end. Naturally aspirated. All happiness occurs below 6500 rpm. Instant torque on demand all across the tach.

 

So I have chosen on a GM performance (crate) 376/430. It doesnt come with manifolds (which I need swap manis anyways) no accessories, or harness/ecu

Advice on harnesses/accessories. Or “should i” or “shouldnt”
id rather not spend 12 to 1300 on the “kit” to just send it back out with my s2k harness for a dual ecu setup costing another 999+ Seems expensive just for a stock tune and oem ecu.
(Which I do need) just thinking “budgetier” or I can try my hand at doing the splicing/repinning. Which they say is not to daunting but need to be good on a MM.

if im not mistaken I could get a ls1 dbw harness / ecu / pedal/ lingenfelter reluctor conversion, and then just need a ls3 tune? Which I could possibly save on and either still send for pro harness dual ecu setup, or still follow instructions and diy it.

This is my first swap (atleast for this caliber) and i got my friend say go holley efi and quite thinking honda (import) standalones and I just want to get it in and runnin lol. Just want stock tune/ecu/dbw

 

I wouldn't bother trying to make an ls1 harness and etc work with an ls3 and bring that lingenfelter box into it. Just buy the right standalone harness for the job and be done with it.

 

My GM crate 376/430 came with F-body cast iron exhaust manifolds straight outta the GM box. PSI conversions supplied an 08 Corvette ecu (vats, evap and rear O2 emissions removed), harness, O2's, pedal and mass air sensor. Started on the first crank, no issues, OEM drivability. Can always go back later and play with cam/springs/tune. The forum is full of threads with used stuff that's broken in a week or two, "home made" harnesses with mismatched computers and LOTS of time spent trying to get things working correctly, which sometimes seems to never happen. That's what steered me towards a brand new engine and a "stock" ecu with a "new" harness along with the ancillary bits guaranteed to be compatible with the ecu.

I used an ICT Billet low mount 145A alternator, a Caddy CTS-V power steering pump bracket and an Alan Groves low mount A/C compressor --- all for the Corvette pulley spacing that the GM crate motor comes with. Couldn't be happier.

 

So to keep my stock dash/instruments im gonna be running dual ecus. tweak’d performance can do this. I found out all I have to do is supply the s2000 core harness and they make the rest. Still pricey but at least I dont need both harnesses and then ship it off for more work.

 

Or is this just for the stock chassis guys so everything works together?