Need some help with Brake issues

I change the power brake booster because it was not functioning correctly after changing the booster I was still using the old master cylinder until yesterday when I got a new master cylinder since I did not want the old one to ruin the new booster because of the leak.
I will do some reading up on adjustment of the pushrod. I also did some reading up and found out there may be an issue with the adjustment of the drum brakes in the back causing some air and for them to not believe correctly and that I should get the drums to barely drag and then try bleeding after.
The master cylinder that I received is a little bit bigger but it is for a power brake front disc rear drum car.