which master cylinder/booster can I use?

[19GMC63]

Gonna make a trip to pull-a-part this weekend, and I was wondering which power MCs will fit my truck?

For those of you who've done it, what do I need to do to make them work for my the 'ol gmc?
Do the brackets line up? Brake lines the same size? What about the pushrod?

Also, is there anything special I should look out for? I've heard 3/4 tons have bigger boosters. Which are single diaphragm and which are dual?

Any input/help would be much appreciated. Pics would help too.

[19GMC63]

anyone?

[Chevy Fleetside]

I have a booster from a 68 which was straight when installed. and I have one from a 72 which pointed down. If you use any booster the two original holes will bolt up and you will have to drill the rest. You will also probably have to extend the brake rod to make it reach your pedal.. The original power brake booster I started with was from a 75-79 ish style. It bolted up and I drilled the bottom holes for it. Had to do some brake rod work to it also. I think now I am going to go with a 90's booster and just bolt it to the firewall and extend the brake rod as needed... I think it will be a much cleaner look.. They all pretty much fit but will need some fab work to work. If you want a bolt in then if you can find one for a 64-66 they you will be in business.. A disc brake master should bolt up to it with no problem.. I am talking about a dual pot master..