Ok, here's your correction.
Back around 1975 Direct Connection (the predessessor to Mopar Performance) introduced the D.C. k-member to allow easy installation of a big block into an a-body using factory mounts (74-78 factory passenger car big block units). By 1988 there were four left in the original (and only) run. A friend of mine bought one of those four (for WAY TOO MUCH MONEY - just under $400).
I took a look at it and then started looking around the wrecking yards. It turns out that Chrysler sent out a bunch of poorly made 73-76 small block k-members and hed the motor mount saddles cut off and relocated further back. I picked up a k-member and started building my own k-members, even sold a few. Then around 1992 I discovered that the measurements taken from the actual D.C. k-member were incorrect (slightly). I tweaked the measurements I was using and have been using those since.
So, to wind up a long story. Schumacher mounts still require k-member mods and cost around $150. I can go pull a V8 k-member for $20 at the self serve wrecking yards. I have bought mounts for as low as $10 for the pair.
Instructions on how to make your own D.C. k-member are in the tech pages at www.bigblockdart.com.