decker

Alright. Here's the deal. I've been doing tons of research for my upcoming build. I'm planning on using a Kenne Bell 2.8L blower as my power plant and I'm shooting for ~750-800whp on pump gas. I'm going to fully build the motor, but my question is "What block should I go with?" I've been given two options: 6.0L LQ9/LQ4 block OR a 5.3L LM7 block bored to 5.7L.

I've heard great things about both setups and have personally seen pretty high numbers on at least the 6.0L block. What do you guys think? Whichever block I choose is the full motor I will buy (ecu and all).

Thanks in advance,
Decker

conan

iTrader: (5)

When you say a fully built moter do you mean a forged bottom end or a stock long block. A forged 6.0l bottom end gets my vote, more CI will be easier to make your power goals, Also if you have the $$$ you could get a stoker rotating assembly you would have a 402ci.

Dan Stewart

There is no replacement for displacement.

Go for the cubes.

SweetS10V8

iTrader: (4)

Take the 6.0L, not only for the gain in size but you wont have to bore it .100+ over to get it where you want to run it.

California-police

Take the 6.0L "

98z8uup

iTrader: (7)

Go with the 6.0

decker

Thanks for advice guys. I will be building the bottom end with forged internals shooting for a 8.5-9.0 CR.

I know I'll have more displacement with the 6.0L block, but other than that are the any disadvantages to using the 5.3L block? Will it be able to handle the boost and power?

I'm honestly not too worried about displacement with power plant I've selected ($5k on a blower better do the job).

Thanks again!

decker

Bump

SweetS10V8

iTrader: (4)

Why are you bumping this, everyone has been unanimous, which is very rare.

What information are you missing that you still need?

If you want to run the 5.3L block, just do it, just don't bore it .100 over and expect it to hold 600hp.

Are you looking for someone to tell you its OK to run the 5.3L block? You are not going to overpower any blocks.... unless you bore it .100 over

Buy the stupid 6.0L and just be done.

decker

don't get me wrong. i appreciate the advice. i just wanted to know why i shouldn't go with the lm7 block. i know the 6.0 block is better, but i just wanted to get some perspective on the disadvantages of the 5.3l block. to answer your question, i'm going to be dumping money into this build and want to do it right the first time ... that's why i bumped it. just wanted a few more opinions.

Beaflag VonRathburg

iTrader: (176)

Another downside to the 5.3 at least where I am is the place we use charges you for two hones to take a 5.3 to 5.7. If you are going to add the weight of the iron block go with the 6.0 block.

custm2500

iTrader: (11)

I don't see any posative to useing the 5.3 block. Punching it out so much is going weaken the block and make it compleatly unreliable! Just use the 6.0 block. I don't have a lot of time researching the 6.0 but (from what I have see) any tiny bit of knowledge about motors would tell you it just plain makes sence to go with the 6.0.

djsanchez2

iTrader: (14)

Go 6.0 man, why even waste your time w/ the same motor of lower displacement?

5.3 stroked = 5.7
6.0 stroked = 6.68 liters. Gee which will make more power? (408), hell, bore only mini stroke on a 6.0 will still net more displacement on the stock crank. (370)

Beaflag VonRathburg

iTrader: (176)

You can still run a 5.3 honed to 5.7 reliably.We've done quite a few of them and we haven't had any problems.

A 5.3 has the same stroke as the LS1 3.622. If you stroke it works out to the same stroke. The only difference is the bore.