67 drum woes

[67sleeper]

I have a 1967 1/2 ton with drums all the way around. We put a power brake setup from a 1972 chevy on it. Everything worked great. I took it to my uncle in law's shop to have break shoes put on it (I know do it yourself and you won't have these issues, I got lazy ok) and he took it upon himself to fix my now faulty booster with a 1970. Well this caused all kinds of issues including the brake rod was too short and the vehicle was pulling to right severely. We fixed the rod issue buy welding two together. What I am wondering is could that 1970 booster actually cause the pulling or is it just a coincidence? I have replaced all the wheel cylinders, brake shoes, brake lines up front, master cylinder, and took off the distribution block/proportioning valve to check for any stoppages. I don't really want to spend the money on a new booster since this one cost 100 plus and I will have to buy the rod too but, I don't really see what else could be causing this. Does anyone have any ideas? Any help would be appreciated, thanks.