misterbill

I couldn't find anything in the search, but I want to know.

What constitutes which? What is the difference is power, displacement, head castings, everything? IF there is a sticky, ill be happy to read it. Thanks guys.

chirp_fourth

The ls1/ls6 blocks are in almost every way the same.

The ls2/ls7 are related, but the ls7 apparently is resleeved w/ a larger bore. Somewhat related to the ls1/ls6 block, but redesigned for more strength.

The heads for all 4 are interchangeable as far as I know...

ddnspider

iTrader: (26)

LS6's differ from LS1's in that they have larger bulkhead windows for better ventilation and better high rpm breathing.
LS2's are similar to the LS1's except they have a 4" bore,and LS7's are resleeved LS2's.The heads for all 4 are NOT interchangable.LS7 heads wont work on an LS1/LS6 unless its been resleeved because they need at least a 4" bore.Also they require different valvetrain.but LS2 heads will work on an LS1/LS6

misterbill

thanks guys, so which ones are iron? I know the 5.3 (whats the code) heads are desirable on 5.7 motors. why? What is better about them?

ddnspider

iTrader: (26)

this really shouldnt be in the advanced section,you should read the internals and externals stickys.But as far as the iron block,there are 4.8,5.3 and 6.0 ltr iron block.All ls heads are aluminum except certain LQ9 heads which are iron.5.3 heads are only desirable as a cheap way to raise the compression of a motor.

2002_Z28_Six_Speed

iTrader: (19)

Not all 5.3's are iron.

I think 5.3 heads were used for more compression.
Have heard they might outflow 5.7 heads

LM5 is a 5.3L block that is the same as the LS6 aside from bore. Used in SSR before the LS2.