landonew

Ok, so here is the story. After installing all mods in my sig (except for headers/exhaust/lid) the car dynoed 435 first pull, no tune. Next pull, after 5000rpm heard clanking. Shut her down, pulled oil filter and worse case scenario (metal shavings). Shop thinks its a spun bearing, so that means I need a new shortblock. I want to keep the upper portion of my motor (H/I), but know i will need another cam. Was thinking either

1) 402 ls2
2) 418 ls3

What should i do. Are there any advantages in going with the ls2 over the larger bore ls3/lq9? The car will see a healthy dose of N2O (300 shot), so it needs to be forged regardless. Am looking to buy at the end of next week, but i need the block to be shipped relatively quickly.

Also, I don't know what all is needed for the ls2 or ls3 swap. Does anyone sell a basic kit for this?? I have seen a few threads, but i am getting tired of ordering parts from 60 different vendors.

Shawn @ VA Speed

iTrader: (3)

go with the ls3 block,cost about the same money and you get a bigger bore,bothe will handle same power,you need to change the frt rear and valley covers,relocate knock sensors and extend some wiring,

landonew

So aside from the block itself, all i need is the front and rear valley covers. In addition I will need to relocate the knock sensors, and extend some wiring? I thought there was more to it than that. Good to know.

blackvettejet

I do know the LS3 has a higher displacement and has been shown to respond very well to mods. If it were me, I would go with the LS3 stroker vs. LS2 given the two choices.

What are your goals? Daily Driver or Race Car?

landonew

Well, it is supposed to be my DD, but I am looking at possibly acquiring a beater for DD. regardless I wan't the car to be reliable. I don't know what to do now. I might just have the motor rebuilt.

LSGunZ28

iTrader: (8)

The AFR heads he has are made to adapt to a 3.9" bore? If so, is it okay to run with a 4.060" bore? or whatever the LS3 bore is? because I was told its not the best idea to run with larger than a 4" bore.... but if its okay to run with a larger than 4" bore, then I may just do a 418...

if the LS3 bore isnt bigger than a 4" and if the AFR heads he has are bigger than for a 3.9" bore, then disregaurd this....

bluecamaroz28

You need to pay close attention to your CR with those AFR 205s (62cc) heads. You will be close to 12.0 CR with flat top pistons on a 402ci.

Better not go more that 4.0" bore (402LS2) on those heads.