[BR3W CITY]

Alright I'm here, I had to organize my herb n spice collection and that takes a while.


The aluminum 5.3's can take a certain level or boring, how much exactly will be determined by the thickness of the ductile iron sleeves in the block. The reason folks think you can't do so is twofold;

some folks think there is a thin wall of iron and a solid aluminum block which isn't true, the cylinder bores are always the same size (for the sake of discussion lets say 4.2")...what changes is the size of the sleeve in the bore. The 4.8 / 5.3 are the smallest displacement because of a thicker sleeve. Most of them can come up to around the 5.7L mark (chevy's cost saving way of being able to have more-cards in their deck than ever intended. There are odd-displacement versions, and weird all-iron and all-alum versions of LS architecture engines sitting all over the industrial landscape.

The second reason people think you can't, is a misunderstanding of true information. While you can't "bore a 5.3 out to a 6.0", you CAN in fact bore AND stroke a 4.8/5.3 engine to a maximum displacement of more than 6L. You CANNOT however bore them to 4", or run the heads or internals from the 6L+ blocks.

Which heads you do choose to run (and how they are prepared) will be somewhat of a function of the resulting compression you're aiming for, as part of the valve/deck/piston relationship. Most of the time these strokers are being built for all-motor builds which aim for high effort from the engine, meaning it needs compression, it needs to breath, and it needs to rev.

You'll need hardened pushrods, and I'd strongly consider replacing the o.e. lifters with LS7 ones (ALL currenty replacement GM ls lifters are LS7 design, you don't have to ask for them specificially, the part # has been replaced system wide). If your gonna be turning rpm's, then its a good idea to do a trunion upgrade to the stock rocker arms. DO NOT CHANGE THE ROCKER ARM GEOMETRY.

Cam and springs will also be determined by your goals and parts choice. Brian Tooly makes great titanium valve springs if you can boss up for them. They are one of the only springs that will keep seat pressure after long periods of low-ramp high-lift cams.

my brain is tired for now. Let me know what else you'd like to know, I can work out some more.