just wanted everyone to know i just came back from my machinists shop and we weighed a LS1 block (103 lbs) and a 6.0L truck block (206 lbs) I helped lift each one on the scale so i know personally those are the weights with out main caps & completely bare. i hope this helps people with any confusion

 

the ls1 block had sleeves in it?

 

I always figured it was twice the weight but never put either one on a scale

 

According to GM service manuals Iron block (BARE- no caps) is 92 lbs heavier.

 

yea - that's a semi accurate rule of thumb that alum weighs about half of cast iron. it's just that i read that the ls1 block weight 107 w/ out sleeves, and that the iron block weighed only 65lbs more than the aluminum........ that was in the how to build a high performance gen 3 motor and the other book - i think it was just called highperformance chevy ls1/ls6 or soemthing like that. where'd they get their numbers??? they're publishing this stuff--- you'd think it'd be accurate.

 

the LS1 had stock sleeves. as far as what the gm manual says i bet that info goes from here to there and everywhere and it might be the block with out liners, but i was AT the machine shop I helped lift the iron block (it took two of us) and i lifted(by myself) the alum. block. same scale, same time.

 

that seems about right. My fully assembled ls1 (block, crank, pistons, rods, and a few other things) seemed like it weighed about as much as my 6.0 block alone. From what the the machinist told me when he bored the 6.0, it took him twice as long as it normally would, because the metal was so hard.