Hey y'all, my question is about an 07' (new boody style) silverado that has a iron 5.3 with 799 heads. What dose this motor share in common with the L33 H.O.? ( pistons, cam,ect.) I notice the throttle body and intake are different than mine (07 silverado classic 5.3) possably going to buy the motor and swap some parts, thanks for any info

 

Sunday morning bump

 

As far as I know internally they are the same. Some of the newer ones do however have the active fuel management which I believe is computer controlled, but I don't know for sure that it isn't something internally as way...

 

thanks man, i think i'll just buy the thing and see first hand, i know the top end is good but the truck is MANGLED, pretty hard to imaging someone was in it when it crashed, both motor mounts are riped apart at the rubber and the acc. bracket is split in half, i didn't see any oil or cracks but you never know, i can get it for $380

 

The all aluminum 5.3 (L33 motor) has flat top pistons with coated skirts and is 10:1 whereas a regular 5.3 has dish pistons and 9.4:1....

The L33 also has floating pins compared to the pressed ones in a reg 5.3...another good thing is that the L33 has the ls6 heads which are the best factory heads you can get and are worth at minimum $300 by themselves...I got my L33 for 300 which I couldn't pass up either, go for it

 

Also the L33 has a slightly hotter cam (more duration and lift) than a reg 5.3

 

thanks wild, but how are they making up the differance in compression? my LM7 5.3 has 9.4:1 with dish pistons and 5.3 heads, i would assume the motor would NOT have reverse dome pistons having the bigger combustion chamber 799's

 

First , the L33 uses flat top pistons as previously mentioned , and probably also either shorter deck height and / or thinner head gasket or both .