does the 5.3 block have the same bore as the 5.7 ls1? or does it have the same crank? my bud has a truck with the ls1 5.3 and would like to know , my thiught is that if it has the same bore then you could use the 5.7 crank to make it in to a 350, which would be bad ***,,,, any one ever heard of this before?

thanks

 

Crank is the same, but the bore size is smaller. You can overbore up to 3.910 (.125 over), which will net a 352 cid motor. With properly done 5.3 heads, 400+ hp is very possible without any power adders.

 

Yeah.. I was wondering the same thing.

 

blownmero i hate your *****... <img border="0" alt="[Fluffy]" title="" src="graemlins/fluffy.gif" />

<small>[ August 19, 2002, 03:01 AM: Message edited by: tbone4232 ]</small>

 

Hey Todd how did you do your calcualtion on displacment?
when i do the .010 over (3.910 bore, 3.62 stroke)
i get 348ci

using this.
http://www.rosspistons.com/CR%20Calculator.htm

 

stock stroke is 3.662....I usually do my calc's here:

www.prestage.com/carmath

Todd

 

Actually, the stock crank has a 3.622" stroke... A 3.910" bore w/ a stock crank is around 348cid.

 

The 5.3 block is cast iron, while the LS1 motors use an aluminum block. That's probably the biggest difference right there. The 5.3 blocks are 96.01 X 92.00mm (bore x stroke), the LS1 is 99.00 x 92.00 mm.

 

Todd, does the 5.3 block have a different crank?

 

My bad guys <img border="0" title="" alt="[Sad]" src="gr_sad.gif" /> George is right...the 5.3 uses the same crank as the LS1. Everything is interchangeable on the outside. There is one missing bolt hole for the alternator on the 5.3 block (center hole for bracket). Mine had no issues with only two bolts in the alternator.
Todd