Black Jacks

My LS1 has just over 140k on the clock and am in a position to build a block for it and am weighing my options here. I found on Craigslist a complete LS6 longblock with 30k on it and a LS2 shortblock with 60k on it and they are both very similarly priced so I am completely torn.

My car came with a 239/241 cam and a set of 862 heads with 64cc chambers and I plan on reusing the heads and cam and looking for a FAST with direct port plumbed and running a 100 shot.

I guess I just need some advice and peoples experiences/opinions here on which way to go and if anyone has gone this way and the results they found. The car is a daily driver so I don't want to go crazy on the nitrous and start breaking things right and left so which shortblock would you go with and why?

IRONFIST

You should go with the LS2 block, it's got a bigger bore which will allow you to build more power not only due to an increase in displacement but also because valve shrouding is decreased.

1nasty86

iTrader: (63)

I vote ls2

garygnu

I would say go with the ls2 also.I would consider a custom cam also.with the ls6 you could port the heads and get a cam from Patrick-G and make great power also.

Patrick G

iTrader: (14)

I vote for LS2 block. Bigger bore and 18 more cubes are a good foundation for making more power on and off the nitrous.

yonerhottlt1

iTrader: (21)

+1 for the LS2. Bigger bore, more cubes, should have more compression than an LS6 and will give you more room to grow later.

bww3588

iTrader: (49)

I vote for the ls2 as well, however, I would look into a different set of heads. The 5.3 heads with a smaller chamber will drive compression up since your running nitrots.

BRDMAN

iTrader: (8)

LS2 gets my vote..

Damian

iTrader: (89)

The LS2 will make more power everywhere on or off the nitrous, mod vs. mod.

Throw that internet phenom cam in the trash and buy a camshaft that's actually designed for nitrous. Nitrous likes a 6-8 degree split for best results. If you must retain gigantic duration, use something like a 232/240 or 234/242.

Also keep in mind you will need to change the reluctor on the crank to put an LS2 in an GEN III car.

NVUSZ28

iTrader: (5)

LS2. The LS6 is a glorified LS1.

VIPRETR2

iTrader: (63)

That's just bad information there. The LS2 may have either 24x or 58x reluctor depending on year. If it happens to be a 58x reluctor engine and you don't want to take the motor apart you can buy Lingenfelters signal converter box.

https://ls1tech.com/forums/15715001-post6.html

http://www.lingenfelter.com/mm5/merc...w=&range_high=

Good luck, oh, and I vote LS2.

2002TransAmKid09

Amen. LS2 gets votes across the board. could bore it up to a 418 safely, but your heads are going to determine the low end power or highend with air restriction. ive found that LS6 heads make more torque than the LS2 or L92's so they would be better for nitrous, BUT if you plan on boost later then the LS3's would be worth looking into. and your cam is alot like mine but you will put down way better numbers with a built 2.

Black Jacks

Even if I was running a stand alone with 110 in it?

The cam was in the car when I bought it, it's an LG G5X3 239/242 600/610 114+2 and the paperwork that I have from the previous owner says it was a custom grind from LG specifically for nitrous. I would be very interested to hear yours and others advice on a better spec for nitrous as I am kind of a newb.

Again please forgive the ignorance but would the factory LS6 heads be a better way to go over the modded 5.3's I currently have? The car is a daily driver so I don't have any plans for boost in the future because I plan to build a dedicated drag car.

Thanks everyone so much for the information here I really appreciate it!

2002TransAmKid09

im not sure to what extent your 5.3s are built and what the intake lift is on your cam, but as long as you have good lifters, and a valve spring that compromises for your lift, then you should be good. i say if you have the 5.3s then make them work

Patrick G

iTrader: (14)

That is not the G5X3 specs. The X3 cam uses a 234 .598" intake lobe and +4 advance. It is an outstanding nitrous cam.

Black Jacks

They have been CNC'd to 64cc's and have stainless 2.02 intake valve and 1.57 exhaust valves. The car has Morel linkbar lifters and morel springs good to 650 lift.

2002TransAmKid09

to be honest i dont know much about the morel linkbar lifters, but from what it sounds like, you will be good man. then again another opinion never hurts. for just a nitrous build you dont need different heads. just remember 2 - 2.5 retard ignition timing per 50 shot on pill. 100 shot is 4 to 6, just depends on what they tune says. have fun man!

sabastian458

iTrader: (5)

How much was the ls6 long block?

2002TransAmKid09

im not sure, but maybe this could help

http://www.texas-speed.com/c-123-engine-blocks.aspx

sabastian458

iTrader: (5)

I was curious about how much the used 30k ls6 was being sold for. I have a 16k mile ls6 and was considering on selling it.