LS1 Based 427 or 426, I need some advice

Hello all.  I am a new member but long time reader of GMHTP.  I own a 2004 GTO with an LS1 and T-56 trans.  I have aquired a 9k mile used GTO LS1, and plan on tearing it down and resleeving for bigger cubes.  I have seen some articles on 427 LS1 and LS2 based engines.  But since then, tech. has changed.  With the new LZ7 style heads, and better cam designs, I am looking to utalise all of the top of the line parts for a fail safe reliable big cube motor.  I am looking for any and all help as well as feedback on parts.  I have a great freind who owns a machine shop who is going to help e with the work on the block and resleeving.  I will assemble the whle thing and install it myself.

I want to thank anybody who responds.  

BTW, here is my baby.


 

Hi. I dont know what hp numbers you are looking for, but if you are going to use top of the line parts, then why not use the new LSX block? Do you know about it? It can be bored and stroked to 511 cubic inches, and gm says it handles 2000-2500 hp. It costs less than $2000. I would think that for high horsepower and big c.u., the lsx would be the obvious choice. It has much thicker cylinder walls than a resleeved ls1( I think). Also, you are using an aluminum block ls1. they can only handle about 600 hp from what ive read. the iron block is what everyone uses for high hp applications. If you want to stick with an aluminum block, go with the ls7, c5r, or world products ls7x blocks(all much more expensive than an lsx block, and cant handle as much power).
I would not call a resleeved factory aluminum block "failsafe".

just my 2 cents.  

My biggest issues with the LSx block is deck hight, and the weight.  I want to stay aluminume to keep this portlyt machine's weight down some.  The deck hight may become an issue with the headers I have in the car as well as what is avalible on the market.  Higher deck hight will require custome headers to be made.  And back clearances on the steering rack due to it's firewall side mounting of the engine cradle.

I am also weighting my options.  I might to some block prep to keep in one piece for an extended period of time.  Only due high 300 or low 400 cubes.  Then Pro Charge it with 10 psi.

The block I have in my posesion was already pushing 750+ RWHP in an A-4 GTO with heads and cam as well as an STS turbo system pushing over 10 psi.  These LS1 (really an LS6) engines can take quite a bit of HP.  

Its true tech has changed and engine block choices have changed too over the years. Each option has its own good and bad points. Here is a rough list of those options for you, should you choose to stick with an aluminum block:

1)Stroked LS1 (383-396ci)
2)Stroked LS2 (402-416ci)
3)Stroked L92 (414-427ci)
4)LS7/C5R (427-441ci)
5)Warhawk (454ci max)
6)Wet/Dry-sleeved LS1/LS2 (455ci max)

Among these the stroked LS1, LS2 and L92 are easily the cheapest, one of the most reliable, and provide the greatest ease of install. If you are planning to stay naturally aspirated or use only modest boost, the block's strength shouldn't come into question unless say the sleeves were installed improperly or the motor was detonated quite horrifically. If you are looking for a "fail safe reliable big cube motor" I'd think long and hard about resleeving the block due to potential installation issues, and at the very least have a reputable company such as MTI or Darton install them for you.