Adapting Chevy master cylinder 9/16-18 IF 1/4 to our 3/16 line help

[CWccw]

This looks to be a promising conversion but the info out there for it is old.

I have almost everything needed to do this, the AC Delco 18M217 master cylinder, a 1/2-20 x 3/16 line fitting but just need one more part. A fitting to go from 1/4 line to 3/16 line in the 9/16-18 flavor. Does anyone have a solution to this?

 

[diverscale]

something like this?

Dorman 785434 1/4" x 3/16" Brake Adapter, Hose, Lines & Fittings - Amazon Canada

or this Dorman 785432 3/16" x 1/4" Brake Adapter, Hose, Lines & Fittings - Amazon Canada

?

 

[CWccw]

something like this?

Dorman 785434 1/4" x 3/16" Brake Adapter, Hose, Lines & Fittings - Amazon Canada

or this Dorman 785432 3/16" x 1/4" Brake Adapter, Hose, Lines & Fittings - Amazon Canada

?

Those dont specify enough information. Thats like shooting in the dark. I know people have done this conversion before and would like to know what they did. Closest post to someone doing is is from 2010.