[57taskforce]

All this talk of cannibalizing 5th gens is giving me anxiety!
The LS3 and the L99 are very close brothers but not the same, aside from AFM and VVT the L99 also has different pistons with Valve reliefs that lower the compression slightly. Also the 821 heads in the LS3 are the same physical casting as the L99 but have Lighter sodium filled valves that support more Rpms. The LS3 has a higher factory redline at 6600 vs. 6200 in the L99. The L99 will have 823 heads. Keep in mind it’s critical to get a healthy engine, the aluminum 6.2’s have very very little over bore. .020 is really pushing it. There are salvage sleeves available but it’s normally cheaper/better to get a new replacement block. If you get an L99 your gonna want to delete the AFM before you do the swap. The AFM lifters are a widely known fail point. Some reading on Camaro5.com will help you understand the animals your dealing with here. That’s nearly an extra $1,000 on top of normal cam swap prices. VVt is in the eye of the beholder. When I cam my car, I’m going to likely delete it because I’m building it for an LSA supercharger, so vvt really won’t be necessary. For an NA build I would keep vvt. The L99 is 400 hp in stock form and the LS3 is 426. The vvt is what allows the L99 to run neck and neck with the LS3 speed wise while overcoming less HP and more driveline losses thru the 6L80E. The 5th Gen cars love 3:91’s plain and simple.(your C10 will as well assuming similar tire diameters) Don’t stop short at 3:73. 4:11 is an option for us but the the 4:11s in the Camaro irs aren’t as strong as the 3:91 is so most guys steer clear. 6l80 In Camaro form is good to about 650-700 whp without sticky tires. The 6l90 in the ZL1 is easily good to 950 WHP in stock form. I’ve seen guys run 700+ whp thru the 6060 without issue. The earlier 6060’s Have some Syncro issues but not on a huge scale. If you end up with an 6l80 or 6l90 Jannetty racing makes a great bolt on tranny dipstick kit. The autos don’t have a dipstick from the factory. It’s a good idea to replace the LS3 oil pump with a melling high volume, the stock pump is another known fail point. The L99 uses a different Factory high Volume pump to run the vlom. The L99 and LS3 both are stupid strong engines, lots of them have been pushed to 800+ hp with very nice reliability, it’s as much in the tune as it is the parts that you throw at it though. I prefer to see the 5th gens un cannibalized but I do realize it’s much better to let the organs live on after death!
As much as I love my old trucks, this one is my real baby.

Another good avenue to look for in swap motors is the L96, L92, and LY6. All will have the bad ass 823 heads., the 96 and LY6 are Iron 6.0’s that are plain tough as nails. The 92 is pretty similar to the LS3 and L99 in that it’s an aluminum 6.2.
Hope this helps muddy the water some!