Mounting a modern chuck on an antique lathe

[Robert Champagne]

My new old lathe is a Frank H. Clement patternmakers lathe. It probably dates from sometime around the turn of the last century, as Clement was bought out by American in 1898. It has a 20" swing and about 60" bc, and weighs about 1300 -1500 pounds. I have been happily turning big bowls on this using the faceplates I got with the lathe, but really miss having a modern scroll chuck (I have a Sn2 on my 12" Oliver). I have a used Stronghold that I would like to put on this lathe. The spindle is something like 1 5/8" by 7 tpi. I am planning on sending a face plate to BestWood Tools so that they can match my spindle size for a custom adapter. I have two adapters for the Stronghold: a 1 1/2" x 6 TPI and a 1" x 8 TPI. I am leaning toward having them cut the adapter to fit the 1" x 8 TPI, as I have another smaller chuck that is directly threaded to this size. My question is: if I have it cut to 1", and reamed for a MT2, will the spindle adapter be able to hold up to turning 15" to 20" diameter bowls?
Thanks,
Rob
Here are some pics of the lathe:

259121259122259123

[Dennis Nagle]

I think so Rob. Just as long as you don't spin it really fast. I am doing the same thing. My Oliver 20-D as a 1 7/8" 6TPI spindle and I am having a reducer made to 1 1/2" to hold a Stronghold.

Very nice lathe by the way.