Anybody ever mount a 16" plain back 4 jaw chuck to a D1-6 adapter plate?

I'm chuck shopping and there a couple new 15 3/4" to 16" plain back 4 jaw chucks on ebay. I'd pull the trigger on one of these if i could be confident i can find a D1-6 backplate that can be modified to fit. I can imagine the chuck mounting bolts might interfere with the cam-lock pins but without actual dimensions, i'm left guessing.

Depends

D1-6" pins are on a 5.250 bolt circle and their lock screws are more or less on the same B.C. meaning any additional bolting on or near that B.C. have to fit between a lock screw and a cam lock pin's threads - and have to conform in large part to the 60 degree apart layout - practically impossible on the four bolts the chuck has

The cure of course is to have a big enough back plate and chuck bolt circle to clear the details on the smaller B.C.. A similar but less desirable cure is to just have a THICK enough back plate to suit

A place to start is ask seller for B.C. diameter on the chuck before you buy it

ON EDIT

practically impossible on the four bolts the chuck has

Click to expand...

A trip to the shop shows me the above isn't very accurate

One backplate shows plenty of room for four 1/2-13 on 5 1/2" B.C. -assuming plate was thick enough for lock screw tapped holes other side

Thumbnail is screen shot

And showing the hidden lock screws back side interfering with two of four chuck mount holes. The reason for either thickness or larger bolt circle

Thanks John. I've got a question into the seller on the bolt circle diameter. My ultra-precise measurements from the pic in the add indicate it may be cutting it close. Worst case is i just buy a slightly used 4 jaw in excellent condition with the proper adapter plate already mounted.

Mark