bobd54321

I believe the 496 is a bored 454. I also think they changed the firing order but i read this a year or so ago so i cant remember all of it.

joshluther

iTrader: (24)

I have an all aluminum 2005 5.3 in my shop right now with 10K miles on it. For the right price I'm sure the owner would sell it. It came out of a 4x4 ECSB it's the 5.3 "HO" L33.

The aftermarket support for the 8.1 is really limited.

NO-OPTION-2002

iTrader: (2)

8.1L (496ci) = 4.250" bore x 4.375" stroke = 496.52ci
7.4L (454ci) = 4.250" bore x 4.000" stroke = 453.96ci