i want to do an engine swap in my sierra, how beneficial is it to have an aluminum block(ls1 or something) vs. the lq9? i want good performance, but i also wouldnt mind lightening up my front end, how much weight difference is there from the aluminum blocks to the iron blocks??? if i could just get all the pros and con's of both worlds PLEASE and thank you all

 

roughly 90lbs between the two

makes a noticalbe difference in the fbodys. with an iron block frotn end will sit alot lower

 

my front end sat up about 3/4'' when i swapped in my LS1. No real big handleing difference though.