Looking to upgrade my C5.

Has stock LS1 now.

Thinking of dropping a crate motor in.

I want the least pain during the process.

Which would be the easier choice?

Dropping in a LS6 or the LS7?

Im sure it has to be the LS6 due to the fact it actually came in a C5 body from the factory.

Just wondering what id hear here about it.

 

i think u answered this one ur self but yeah the ls6 will drop right in, LS7 will be a hassle and coast a hell of a lot more not to mention dealing with the dry sump oil system and moving various engine bay components and relocating the battery to the trunk

 

Actually i just realized that the LS3 has more horse than the LS6.

But compared to the LS7 im sure the LS3 would be an easier drop in. Due to the dry sump issues you mentioned.

Plus the LS7 is about 14 thousand dollars!

I just like the look of my C5 sooo much more than i like the look of the C6's.

But love the power of those C6's.

Going for best of both worlds.

Not a big fan of rebuild engines.

Id rather have a brand new high production factory engine. With atleast some what of a warranty.

 

Does the LS3 drop right in??? I dont know. I heard a member on here mention it. I know th LS2 does but wasnt sure about the LS3....

 

yeah well for the same price as an LS7 u could build a nice LSX block or i know u can drop an LS2 straight in with the LS3 u have to change the valley cover n timing set, but TSP has LS3s and all the parts to drop an LS3 into the C5 i know what u mean i recently bough a C5 i had the money for the C6 and was going to get one but i just like the C5 better

 

Any LSX motor will fit. Just depends on what your goals are as well as time and money. LS6 would be the easiest swap. But for $6000 (if you can even find a crate) why not do a head and cam swap and get even more power than an LS6.

LS2, LS3, LS7, LS9 use a different PCM operating system and high speed LAN. Not sure whats involved in making everything work properly.

 

The C5 just screams Vette to me.

The C6 says im a vette but i kinda wish i was an import. Looks like a poser to me.
But i have to say the C6 is ALL VETTE under the hood.

 

Yes i agree. The title of this post should actually be LS3 vs LS7.

LS6 just doesnt make sense. Other than the fact it is a direct drop in.

I just hadnt thought it all out before posting.

Thanks for all the input.

 

If you start with a new block and purchase forged parts for the bottom end all the other latest technology in parts,then I would consider that engine to be hand built and superior in performance and reliability to say a LS6 /LS2/or LS3 crate engine. To me the term rebuilt refers to a engine that is OEM in stature and certainly not to one that was hand assembled by a good engine builder with superior after market parts...just my two cents.

 

LS6 about $6,000 all said and done

LS3, about $8,000 with computer and new headers change too.

LS7 about $20,000, need a dry sump too. Better clutch, bigger radiator for the cooling, headers, Oil cooler yatta yatta

 

I agree. If your LS1 block is still intact you can have it built and way outperform a crate LS6/LS3. Open it up to 400 ci and work the heads. You will be make more power, be more reliable all for less money.

 

I like the ls3 idea... that is one solid motor and the ls3 heads flow so well.. the ls7 is a great motor but they are still so much...

 

A 99+ LS1 does not need to have any of the electronics changed to work with a newer LSx motor. If you buy one built from a vendor they can build it with a the proper crank reluctor wheel. If you buy a crate motor, Lingenfelter sells a box to convert the newer crank signal (52x) to the older 24x crank signal. Then it's a matter of getting knock sensor extension and a cam position extension (LS3/LS7 mount them differently). Depending on how complete the motor is you may need to do some rewiring or replacing newer sensors with the older style you currently have. After that it's merely a matter having a tuner program the PCM for the engine.

Your forum name indicates you have a 1997. The '97-'98 PCM's did have some limitations and you should talk to your tuner to see if they can work with the existing PCM and a big cube LSX swap. Otherwise there are some write ups to swap in a 99+ PCM. Which would add some to the cost, but not a whole lot.

Personally I would look at 416/418 stroked LS3 shortblock from a supporting vendor. They can be had with the correct crank, sensor extensions and other miscellaneous parts needed for the swap for about $5000. Add whatever heads, cam and intake you want and you're good to go. The LS3 based stroker will also not require a dry sump setup and therefore drop right in. You'll be about 10 cubes short of an LS7 but thousands less in cost.

I would not recommend an LS6 swap simply because the small gain is not worth the hassle. You could add a mild cam and aftermarket ported heads and make much more power.

 

^^ Correct an LS3 416 is about 8-10k for the long the long block and it will drop right in. The engine , coming from us would be much stronger than the factory crate engine.

 

do yourself a favor and get a built motor. And this venture will set you at 10k or more....Id know