hey ken, im not sure if your in the same boat since you dropped in a new motor. but when i had my shaker problems. i jacked up the motor itself under the oil pan with a piece of wood, then loosened all the motor mount bolts on the block and on the car and then lowered the motor back down. retighened the bolts. i was able to gain about 1/2" i took it as that when the motor was being dropped in, they had the hoist supporting the weight still so it wasnt fully seated in the cradle..
just thought id throw it out there