The major difference is that the 88 has a different crank, with a gear that drives an internal balancer. The oil pump is art of that balancer.
The 88 has the oil filter mounted in the pan, accessed through a huge plug, where the 87 has it on the side of the block.
FWIW, I have heard that the 88 crank is stronger due to the gear, and can be swapped into the earlier engines. Don't have any verification or proof, however.
Otherwise, the 87 and 88 Dukes are essentially identical. Right down to the ignition (coil packs) TBI and the accessory drives.
If any of the mounts/brackets are different, it probably has more to do with differences in the cradle, than the engine.
[This message has been edited by Raydar (edited 08-06-2011).]
