Look man.
**** General Motors and all.
Have two LS fleet trucks, 4.8 and 6.0.
That 6.0 is ****ing mean. Laughs it's ass off at the Ford 6.2.
4.8 ain't no slouch. Can put the Silverado sideways on wet pavement if you get after it. Fun little V8.
The best thing to do when considering an LS motor is to remember it took GM 100 years to get it right, so you can cut them a little slack and use the only not trash motor they build. If it makes you feel better, throw the garbage vehicle it comes out of away in a creative way. Set it on fire. Make a set of Ford valve covers for it. Idgaf whatever blows your hair back.
The LS motors are impressive. Ain't no hemi, and can/will never have Dodge levels of power without some heavy spending. But for a budget build, they're the route to take if you want a cheap way to build a reasonably powerful engine. Mounting it may be a different story.
GM is cheap performance. If you're not going the 5.7 Dodge route, then go for the budget build with a 5.3 with diy ported Cathedral port heads, cam, and programmer, easy 400+ build. 4.8 if you're going the boost route, and you can reliably expect 450+ at the wheels with some dyno time. 6.0 for a screamer n/a build.
If you want something with more torque, 5.7 or 6.4 Dodge build. I own a 6.4; have yet to meet a stock V8 that can touch it. They 6.4 Dodge can be brought into the four digit HP club for the same money you'll be dropping on a 800HP GM 5.3 build as well. The difficult part with Dodge is fitting the damn hemi heads into, well, anything. They're massive engines, and if you think a 351 is bad, just try to cram a hemi into anything.