SWAP vs REPLACEMENT
I get calls and emails weekly regarding this so I will do my best to kindly explain the difference.
A "SWAP" is when you want to transplant an engine into a vehicle that did not originally come with this type of engine. Generally if your vehicle is pre 1998 than you will be in the "Swap" category and I sell engines for this. Although if your location requires SMOG than I don't, sorry. You will need a "complete" engine, i.e. engine, harness, computer, water pump, starter, alternator, ps pump, intake manifold, exhaust, etc. as seen here. This is the ONLY way I sell engines, I do not sell parts.
A "REPLACEMENT" is replacing a worn out engine with the same type of engine or similar generation engine. If you have a 1999+ Cheverolet or GMC Truck or SUV you are in the "Replacement" category PERIOD and I DO NOT SELL engines for this! If you want to replace your 4.8 with a 6.0L and a cam you are still in the "Replacement" category as you do NOT need a complete engine. I do not sell incomplete engines as all you need is a long-block engine as seen here. There are many engine builders like Texas Speed that will build you a long-block to your spec. You then need to have the engine custom chassis dyno tuned when completed.
4.3L V6 to V8 Replacement / 5.3L to 6.0L / Etc - Even if your truck has a 4.3L V6 your are in the "Replacement" category as well as switching from a 5.3L or 4.8L to a 6.0L since your truck "was" offered from the factory with these engines. My engines come with a modified OEM harness and would NOT be compatible for this project - everything you would need is available at your local wrecking yard. The 4.3L to V8 "replacement" is bit unique but offers its own set of challenges to be SMOG legal and legit. Your VIN number is embedded in the ECM and needs to be retained. Your VIN number also indicates what engine the vehicle is equipped with. So you need to essential run the new V8 on your existing computer and be retuned. This is a limited market and something I will NOT get involved with, sorry. Switching or Replacing a 4.8L with a 5.3L or 6.0L is a bit easier since you just need to re-calibrate the ECM to the new larger engine. When doing this conversion your new 6.0L will start and run on 4.8L calibration for example, but any throttle position that requests PE (power enrichment) will cause the larger 6.0L to run lean and damage will occur. I recommend custom tuning at this point although a "mail order" re-calibration will get you pretty close. I do NOT offer this service!