later model master cylinder on a 69?

[oldtrucknut]

Here's what I'm trying to do-

I have a 69 C10 with power disc brakes (front end from a 71). I want to get a new master cylinder with a plastic reservoir. For looks and because the cap shouldn't leak, unlike the new cast iron mc i just put on.

I tried a MC for a 1990 1/2 ton. Close, but no cigar. I might look at a Blazer MC next. Has anyone here had this situation?