1991 5L GM into 8 Firebird
 

I need a little advice on the motor mounts. The new mounts I bought for the block look to place the mounts right over the crossmember when the block is in position. The stock frame mounts for the firebird are looking for the block to be about 4" to the rear. Is there a set of frame mounts without the offset that will use the existing holes in the crossmember? Any suggestions for off the shelf parts to minimize special designs or drilling?