I bought a Winters #SR 3605 V8 Centre Kit, it comes complete with the pinion installed in the case, a 3:78 ring gear, Wedge lock gear drive posi unit, one set of change gears of your choice, bearings, shims and O rings. I also ordered the optional plain rear cover, rather than the finned standard cover. I am using 40 Ford side bells with big bearing 9" housing ends, & brakes, & push in 31 spline axels. They claim this rear end will handle 500 HP, as long as your aren't side stepping the clutch with slicks on the drag strip. I searched the web, and phoned a number of people that sell these units, but could not get a definitive answer on "HOW" to set this rear end up, only the specs, so I decided to figure it out myself. This is how I did it. The side bell preload and pinion backlash, is set much like the stock early Ford rear end, only you are using shims on either side of the carrier, instead of gaskets, between the side bells. The pinion is factory installed in the case, and it's pre-load is set a 20 in.lb. Therefore, you do not need to mess with that. You will need a set of "set-up bearings", so I bought another set of 25592 Timken carrier bearings, and a new set of 25522 Timken cups, which I installed in the side bells. I had the 25592 carrier bearings honed out so they would just slide on and off the carrier, making the set-up easier. Pic. # 1 Side bell preload with the Wedge lock carrier installed, should be .007. This is done by adding shims and the spacer, between the bearings and the carrier, so there is absolutely no side movement of the carrier, when the center section is bolted up to the side bells. The .007 is added to the total for the pre-load. I found this impossible to do, without being able to get a feller gauge between the carrier and the carrier bearings, with the assembly bolted together. I machined four spacers the exact length of the center section, out of 5/8" DOM tubing and threaded them 3/8-24, on both ends, to space the side bells apart, the same distance as the center section, with the carrier, shims, spacer, and bearings installed. Pic.# 2. Stand the left housing on the ground, and assemble the carrier and shim pack with bearings, and then bolt the right side housing together, lift it up on the bench for your measurements. Pic#3. Do not bolt the Ring Gear to the carrier yet, as it is much easier to measure for the required number of shims without it in place. Double check, that the carrier is tight, and has absolutely no side play between the side bells, then add the .007 for your carrier pre-load. Once you have the carrier pre load established, you can bolt the ring gear to the carrier, taking care to position it correctly, and torque to 60 ft. lbs. in steps, using Red Locktite and the supplied Belleville washers and bolts. Pic#4. To set the Pinion backlash, start with an excessive amount of shims on the backlash side (right side) of the carrier. This is to prevent a false pre-load reading. A false pre-load reading will occur if the ring & pinion are crushed against each other. Again, this is easiest to do if you stand the left housing on the ground, insert the carrier, the centre section, and then install the right side housing, bolt it together and then place on your bench to do your checking. Pic#5. Winters supplies shims in the following thickness, .007, .010, .012, & .016. These are some of the combinations you are likely to use. Pic#6. You should take notes of the combinations you are using. Pic#7 & 12. Move shims from the right side to the left side, until a back lash of .004 to .008 with no tight spots is achieved, measured at the upper change gear pinion, without the change gears in place. Pic#10. I made a small clamp to assist in this. Pic#11. The total preload of the assembled assembly should be 27 to 29 in.lbs. measured with a beam or dial style, torque wrench. After completing this set-up, it occurred to me that with the thousands of these units produced, and the precision CNC equipment that machines them, the final set up would probably be pretty much the same, on all of them. My final set up was, .100 to eliminate any side play, plus .007 for the preload, for .107 total. In my final set up, the split was, .050 on the left side of the carrier, and .057 on the right side of the carrier. In addition, there is a .125 spacer on the right side of the carrier in all of these calculations. Pic#9. With the pre-load and backlash established, the checker bearings are removed, and replaced with the permanent pressed on bearings, leaving the shims and spacer in place. Pic#8. I drilled and tapped the right side bell, for a pipe plug 1 3/4" below the centre line of the axel, to fill, and check the fluid level in the ring and pinion, carrier, part of the assembly. There is also a fill plug on the Winters QC unit at the rear left side of the change gear housing. Pic#13 & 14. The complete assembly is reassembled with O-rings sealing the side bells to the centre section, and torqued to 30 ft. lbs. in an alternating criss cross pattern, in steps. I ordered my quick change with a # 3 set of straight cut gears, and a set of # 4 helical gears, which should be shimmed to .005 to .010. Pic#15 & # 16. No sense having a Quick change, with out changing gears occasionally, or when the straight cut's noise start to get on your nerves. I also replaced the High nuts and studs, with Kit #2931, which have shorter studs, & flanged nuts. Pic# 17. I think they look more traditional, and clears the tank, with out modifying it. Measure for axels to the centre of the carrier, parting line inside, and deduct 1/8". Pic# 18. Then add your axels and brakes. I put the car on the road in July, and then went for a 3,000 mi. trip, so this set up works for me. Sorry I was unable to insert the following pictures in the proper sequence. Pictures are numbered left to right, top to bottom.