I'm putting a plan together for a 600-650hp motor. If I decide against the 6.0 truck block are there any year LS1 blocks that I dont want? Ive read not to get a 97 or 98 block and that a LS6 block isnt any better than a LS1 block. Magazine articles seem to contradict themselves. Will any 99+ block work.

Thanks

 

the 97 and 98 block can only be bored out to 3.903 (or 3.902 i forget) vs the later years can be bored out to 3.905. The only difference in the ls6 block is that it has crankcase breathers between the vally's, its supposed to equalize pressure but it truley doenst make a difference. get 6.0L block and go with a 408, thats the easiest way to make 600hp

 

GM designed the LS6 block to twist at higher RPM, and produce more power. It could not do so without the cast-in, bay-to-bay crankcase "windows", so it does make some contribution to the LS6's ability to produce more power in OEM form, and to support more power when building an engine "from the ground, up".

No arguement about the LQ9....if you want to build something insane, it's probably one of the best cam-in-block platforms in the world as a basis from which to build an absolute monster.

 

99 block will work just fine for that power range.