CaMaRo67RS355

iTrader: (75)

ive heard people only wanting aluminum blocks and others only wanting iron... why is this? is one better than the other or what?

Hooligan

Aluminum blocks are of course the lighter of the two, by about 80 pounds. The iron blocks are found in GM SUVs, and I believe are 6.0 liters. The big benefit of the iron block is the strength. They are used frequently if you are planning 700 plus horsepower, and specifically if you are using a form of forced induction or a massive amount of nitrous.

Dex

iTrader: (5)

But how many people have had an aluminum block fail??? There are people in the 9's with the stock bottom end. So how weak can it be???

BIG BAD BLACKSS

iTrader: (4)

Fom what ive heard on the FI forums a aluminum block will start to have issues around 8-900HP after a couple months of hard running.

I chose a iron block for my procharger build cause i want as few things to worry about as possible reliability wise.

mammad78

https://ls1tech.com/forums/generation-iv-internal-engine/608321-aluminum-iron.html

orangeapeel

iTrader: (18)

Weight vs. power levels.

CaMaRo67RS355

iTrader: (75)

i know this is a same thread as in the LS2 LS7 L92 because i wanted all opinions on motors cause i dont know which im deciding to go with yet and wanted to get everyones opinions.

slow trap

iTrader: (22)

the aluminum verses iron is a very debated topic. several builders are dead set the aluminum blocks can handle 8-900 hp while several other builders say they start distorting before that and the aluminum don't stay uniform like an iron and bearings fail quicker. i chose to go with an iron because i don't really care about the extra 80-100 lbs over the nose if there is even a slight chance the motor will live longer.i think it is obvious there is no way the aluminum block is as strong as the steel,the question is at what point will it fail ?

BlackHawk T/A

iTrader: (3)

95% of people should stick with Aluminum.

The 5% that need the Iron block and can live with its weight disadvantage, are pushing serious power. And I bet the weight difference is more over 100lbs when you add other iron components, including heads.