You should be able to put this swap kit together for about $750-$800,depending on your J-yard pricing, and your tax % rate.
- The 8.8" rear axle assembly is approximately $110ish ( if you wait for a 50% off sale then cut that in half, Houston-area yards usually have theses sales about 4-5 times a year, usually on Holiday weekends) depending on your J-yard.
- Southside truss/bracket swap kit $600
- New axle seals, bearings, fluid, and paint $50
You will have a very strong axle assembly that is a bolt-in, and adjustable. IIRC, the 8.8 is about 25lbs. lighter than a 9". I have personally put 800 HP w/ a trans brake to it.