Spool motor mounts available for a 69 340 block?

Could anyone tell me if Spool type motor mounts are available for a 69 block. I am putting a 69 340 in my 73 Duster and it seems the drivers side mount on the 69 is a little narrower on the 69 block mounts and also has only one bolt hole to the rear of the mount? Thanks for any info.