75 nova motor mount inserts

I have a 1975 nova. I had new motor mount inserts installed. Does in matter which angle the metal tabe on the inserts face. I tried to install the motor today and the clam shells hit the tabs and don't sit against the mounts. I could line one clam shell up and the other would go into place if the tabs don't matter. If the angle of the tabs matter do I have to drop the lower control arm to get to the bolts that attach the mounts to the suspension. Thanks any info would help.