Need Help With Replacement Master Cylinder

[mynewtoy]

Hello
My Dads master cylinder went bad on his 1985 M1028 I'm trying to order him one from AutoZone and they're asking me which brake code I looked in the glove compartment and can't find that code. Can someone please tell me which master cylinder I should use my options are JD5 Takes one number JB7 OR JD7 Takes another number.
Thanks In Advance For Any Help

 

[cucvrus]

I think JB7 is correct.
Really it is JB8 Part Number: NM1982 This is the Autozone part number for a new one. rebuilt is M1982. I use them they are good. No need to redesign and buy OEM. These are warranted for life and I seldom have any problems with them.

 

[mynewtoy]

I think JB7 is correct.
Really it is JB8 Part Number: NM1982 This is the Autozone part number for a new one. rebuilt is M1982. I use them they are good. No need to redesign and buy OEM. These are warranted for life and I seldom have any problems with them.

Thank You So Much Your A god Sent