Is this a big block K-member? W/ pics of motor/mounts?

73 - 76 A bodies used spool type engine mounts. They are a superior mount to the biscuit style that you currently have as they do not separate and fail. 73-76 A bodies also generally have 5 on 4.5" bolt patterns for the wheels (many more wheel choices) and disc brakes. If you were to find a 73-76 parts car with disc brakes you could transplant the whole front suspension, get disc brakes, better engine mounts and get rid of the poorly designed 67 only idler are mount. this is all, of course, if you are not restoring a numbers matching bigblock car and you are not too concerned with originality (I think you said your car was a 6cyl originally?). To bolt the 440 (or any big block) to one of these K frames you can buy conversion mounts from Schumacher (uses the mount ears found on all blocks). There are 2 different K frames for 73-76, 6 cyl and V8. Schumacher makes mounts for both. Additionally, you could recoup a decent sum of money by selling off that original 67 (quite rare) K frame and engine mounts.

Or option #2 - keep what you have and find a 383, 400 or 440 that has the bosses - some of them do - think, 400 with 440 crankshaft = 452 if I remember right.

Or option #3 - fabricate some kind of adapter, if possible, to pick up on those two lower bosses near the oil pump, I dont know how well this would work,

Or option #4 - sell the whole deal to me, LOL