This is how I Installed Ford Racing Rear Lowering Springs (PN M-5300-L) on my 2007 GT500. As you all know, the rear end of the of the GT500 sits way too high giving it that 4 x 4 appearance; you can put your fist in between the tire and the top of the wheel well. I just lowered the rear end for now to see how it looks. I used guidance from Snakebite's thread below, but installed the rear springs with the tight coils up. I also replaced the stock rubber lower spring isolators with ones made of polyurethane. Here are the tools I used to install the springs: 1. 3/8” and 1/2” ratchet wrench with 10mm, 15mm, and 13/16” sockets with extensions 2. Breaker bar 3/8” and 1/2" 3. 3/8" and 1/2" Torque wrench. The Ford shop manual advises that the lower shock bolts be tightened with the suspension at curb height. I missed this step so I went back and re-torqued the shock bolts with the tires set on ramps. I chocked the front tires, loosened the rear wheel lugnuts and jacked up the rear end by the pumpkin. I know Ford advises against this, but that’s what I did. I placed a towel on the jack pad to protect the surface of the pumpkin. I placed jack stands on the flat area just in front of the front Lower Control Arm mount. The jack stands were adjusted so the top of the support arms were about 14” above ground level. Once the jack stands were in place, I slowly lowered the axle until the car was resting on the stands and then stopped before all the weight was transferred to the stands. Then I removed both rear wheels. Remove the brake hose bracket bolt with a 10mm socket – do this on both sides. Remove the sway bar link bolt with a 15mm socket – do this on both sides and carefully lower the sway bar. I used a breaker bar to loosen the bolts – they are snugged pretty tight. Once the bar is lowered, you have access to the lower shock bolts. I always wear heavy mechanics gloves when cranking hard on a torque wrench or breaker bar to keep from busting knuckles. Remove the lower shock bolts on both sides with a 15mm socket. Again, I used a breaker bar to loosen the bolts. Note the orientation of the spring's lower pigtail so you can install re-install the same way. Both of mine were centered facing towards the rear. Once the shocks are unbolted, I slowly and incrementally lowered the axle. I was careful to keep the lower shock bracket on the axle from catching on the lower shock mount while lowering the axle. I ended up lowering the axle all the way until the jack was no longer supporting the pumpkin. Even so, the springs did not want to come out. I had to push down slightly on the axle before the spring would budge. Remove the springs on both sides. I chose to replace the rubber lower spring isolators with polyurethane isolators made by Energy Suspension. Their model 9.6106 fit like a glove. They are sold in pairs and cost about $10 + shipping. Here are the stock rear springs side-by-side with the Ford Racing springs. Notice both the OEM springs and the Ford Racing springs are marked with a green slash on one end. This may be an indicator that the marked end should be installed down. The stock springs are oriented as they were installed. The FR springs will be installed with the tight coils up as shown. Install the Ford Racing springs – tight coils up into the upper well. I pushed down slightly on the axle to make room to insert the spring into place on the lower isolator. Here is a picture of the upper spring isolator that the upper coils fit over. I positioned the spring in the isolator the same way the old ones were installed. Once the springs are in place, raise the axle with the Jack enough to reinstall the lower shock bolts but do not fully torque them down yet. The shop manual advises you to tighten the lower shock bolts with the suspension at curb height - I did not do this so I went back and re-torque those bolts with full load on the suspension. Re-install the sway bar links; position both links into their mounts before bolting them down. If you bolt down one link and leave the other hanging, you won’t be able to swing it back up into its mount because the muffler pipe is in the way - don’t ask me how I know this. I torqued both link bolts to 85 lb-ft. Re-install the brake hose bracket on both sides and bolt down. I torqued the bolts to 15 lb-ft. Re-install the wheels, jack the car up off the stands, remove the stands and lower the vehicle. The car is now lower so be cautious when lowering the jack to keep the bumper from hitting the jack handle. You may have to rest the wheels on a block of wood to make sure there’s enough clearance with the jack. Once the car is back on the ground, torque the lug nuts to 100 lb-ft. The shop manual advises you to tighten the lower shock bolts with the suspension at curb height - I did not do this so I went back and re-torque those bolts with full load on the suspension - tires set on ramps. I torqued both lower shock bolts to 85 lb-ft; I did this without having to remove the sway bar links. Here’s the measurement from the ground up to the rear wheel well. It dropped from 29-3/4” to 28-1/4”, a 1-1/2” drop. I also installed an adjustable panhard bar to re-center the rear end.