Funny how some one says" I want a V8" or " I love the sound of a V8" or I just want to put a V8 in my car just because I want a V8" and some one else says "GM made a great engine turbo combo for my car, why don't you just turbo it?' or " My turbo 4 banger sounds good to me" DUDE HE WANTS A V8. If you cant help him out get out of his way
Now that I am done with the "funny stuff"
The front wheel drive LS V8's are the same size as the rear wheel drive LS V8's in there long block configuration. BUT after you put the accessories on they are different size. The front wheel drive engines are shorter from front to rear because the VERY compact accessory's drive system. BUT it makes the front wheel drive engine wider than the rear wheel drive equipped engines. You cant add width to the engine for a KAPPA swap. If you want to use the front wheel drive 5.3 you will need to do a complete custom accessory drive system or convert it to the GM rear wheel drive system. It can be done but it aint easy. Better off just swapping a rear wheel drive engine and tranny from a CTSV or Vette or a GTO. But the engines are in the $8,000-$10,000 range as take outs with ALL needed components.