My 67 car with the 283 has the tall mounts, roughly 2 3/4 height
The 66 Caprice with 396 mounts I have are the same height
The 67 impala 396 mounts I have are shorter, maybe 2 1/4 to 2 1/2 height
So I guess both tall and short mounts were used with big blocks
If you need a set of tall mounts I would part with them, but your 67 might already have the tall ones?
Also, are you planning on selling the 327 engine?