Look for a saginaw box with a 7 and a 6 cast into it. They are supposed to be the strongest version. They have an extra web cast into the case where the sector shaft comes out the bottom of the box. The numbers are not side by side but one on top of the other. Two different input shaft sizes. One is .780 and the other is .800 thousanths. Keep that in mind when you mate up the steering shaft. Also the top little aluminum cover has a allen socket threaded shaft locked up with a 5/8ths jam nut. Try and find a box with that threaded shaft sticking out well above the jam nut. If the threaded shaft is flush with the jam nut than the box has alot of wear and someone has adjusted it to try and take up the wear/slop.
Liz, covid, murdered 10/19/21