It gets even better. Even though GM has adopted a new engine-mount location on the new Silverado chassis, the old GM engine-mount pad is still cast into the 8.1L blocks. Want to bolt an 8.1L in where a 454 came out? No problem. For our pre-runner ORU fabricated these solid front engine mounts to work with the rear engine plate to make sure it stays put no matter how high we sky it.