3. Once you have the tailpipe...
3. Once you have the tailpipe right where you want it and you have made sure nothing is touching the truck go back and tighten up the system. Also, after the exhaust system has gone through one heat cycle, go back and tighten the hardware again.
4.
5. This is not necessary,...
5. This is not necessary, but if you feel the need to tack-weld everything in place go ahead. It's just one more ounce of prevention.
The Final Word
After everything was installed, the truck was strapped to a chassis dyno to see how much power the Yukon has now. As you can see by the numbers to the right, the installation of the JBA parts added 14.5 hp and 17 lb-ft to the peak numbers. Look at the numbers below 3,500 rpm; the JBA stuff really added some low-end grunt right in the sweet spot.
Read It And Weep!
| RPM | HP BEFORE | HP AFTER | TQ BEFORE | TQ AFTER |
| 2461 | 44.8 | 100.1 | 96 | 214 |
| 2552 | 56.2 | 117.0 | 116 | 241 |
| 2643 | 68.5 | 130.2 | 136 | 259 |
| 2734 | 79.2 | 139.6 | 152 | 268 |
| 2825 | 91.1 | 148.1 | 169 | 275 |
| 2916 | 104.2 | 154.8 | 188 | 279 |
| 3007 | 118.6 | 161.5 | 207 | 282 |
| 3099 | 132.8 | 167.4 | 225 | 284 |
| 3190 | 145.4 | 172.5 | 239 | 284 |
| 3281 | 156.5 | 178.3 | 251 | 285 |
| 3372 | 167.3 | 182.2 | 261 | 284 |
| 3463 | 175.6 | 186.1 | 266 | 282 |
| 3554 | 180.6 | 191.9 | 267 | 284 |
| 3645 | 186.7 | 198.5 | 269 | 286 |
| 3737 | 191.4 | 208.4 | 269 | 293 |
| 3828 | 196.2 | 219.1 | 269 | 301 |
| 3919 | 201.2 | 225.6 | 270 | 302 |
| 4010 | 209.6 | 232.9 | 275 | 305 |
| 4101 | 217.8 | 236.8 | 279 | 303 |
| 4192 | 229.1 | 241.6 | 287 | 303 |
| 4283 | 234.6 | 245.9 | 288 | 301 |
| 4374 | 238.5 | 250.1 | 286 | 300 |
| 4466 | 241.2 | 253.8 | 284 | 299 |
| 4557 | 246.9 | 256.3 | 285 | 295 |
| 4648 | 249.2 | 258.2 | 282 | 292 |
| 4739 | 248.6 | 261.3 | 276 | 290 |
| 4830 | 249.9 | 262.2 | 272 | 285 |
| 4921 | 251.6 | 265.3 | 269 | 283 |
| 5012 | 254.5 | 267.9 | 267 | 281 |
| 5104 | 249.2 | 268.2 | 256 | 276 |
| 5195 | 247.8 | 269.0 | 251 | 272 |
| 5286 | 243.9 | 267.2 | 242 | 266 |
| 5377 | 241.1 | 263.4 | 235 | 257 |
| 5468 | 239.5 | 263.1 | 230 | 253 |
| 5559 | 238.1 | 260.5 | 225 | 246 |
| 5650 | 237.2 | 256.1 | 220 | 238 |
| 5741 | 235.0 | 252.9 | 215 | 231 |
| 5833 | 233.7 | 254.1 | 210 | 229 |