Making the best of a bad situation
Hang on a sec;
1) First your control valve inside the booster is broken, It no longer proportions the boost. It's either on or off; and in your case, mostly off.
Secondly their are TWO pushrods!
The First One goes from the pedal to the control valve. It is attached at both ends. and normally, on a mopar, is not adjustable; at least not that I remember. In your case, it appears that the original Chevy end was cut off and a Dodge end was adapted on. My guess is that adjustment was provided there, to adjust for the difference in the two systems. If this end is adjusted too long, it will break the control valve with excessive pedal travel. Then it will take a return spring to pull the rod and control valve back to a sortof "off" position.
Normally, we never need to talk about his pushrod, cuz MaMopar Scienced it out for us , and it's a bolt-on deal.
As to the Second;
the other pushrod goes from the backside of the diaphragm to the M/C.
This is the one we normally refer to when talking about adjusting a pushrod. This Firewall side pushrod has a small adjustment range that we normally use to make sure the Compensating Port stays open.
The booster-end of this pushrod is usually positively located in the control valve, and the other end, has the adjuster on it, and your job, during installation is to guide it into the socket, on the end of the M/C power-piston, to end up exactly the right length..
So since, IMO, your Chevy booster is ka-put, as is now becoming obvious by the hissing during pedal application; Yank it outta there, and get a Mopar one that is pre-engineered to fit your pedal. and get rid of the return spring. Mopar boosters have an internal spring that does the same job.
If the Chevy M/C does not bolt onto your Mopar booster, then get one that will.
The Mopar ones come in three sizes, namely 15/16th, 1 inch, and one and change ( I forget, maybe 1&1/32 or something). EACH smaller one will give a longer pedal travel, and be easier to apply.
The biggest one is harder to modulate, and takes more leg-power, and it takes a bit of getting used to.
I agree with @Garrett Ellison , the 15/16ths was my second choice over 20 years ago, and I liked it right from the start.
A New booster will NOT solve your pull to one side.
The pull could be:
a difference in the contact patches between the two sides, OR
a performance mismatch between the two w/c's, OR
a camber mismatch, OR
a strut problem.
You'll have to do a different diagnostic on that to find out which it is..
Here is a pic; notta Mopar, but you get the idea.
https://www.pinterest.com/pin/vacuum-brake-booster-construction--650770214894398633/
This pic shows the control valve, which I believe in yours is broken . The hissing you hear is vacuum from the engine side of the diaphragm finding it's way to atmosphere thru the broken valve.
Hang on a sec;
1) First your control valve inside the booster is broken, It no longer proportions the boost. It's either on or off; and in your case, mostly off.
Secondly their are TWO pushrods!
The First One goes from the pedal to the control valve. It is attached at both ends. and normally, on a mopar, is not adjustable; at least not that I remember. In your case, it appears that the original Chevy end was cut off and a Dodge end was adapted on. My guess is that adjustment was provided there, to adjust for the difference in the two systems. If this end is adjusted too long, it will break the control valve with excessive pedal travel. Then it will take a return spring to pull the rod and control valve back to a sortof "off" position.
Normally, we never need to talk about his pushrod, cuz MaMopar Scienced it out for us , and it's a bolt-on deal.
As to the Second;
the other pushrod goes from the backside of the diaphragm to the M/C.
This is the one we normally refer to when talking about adjusting a pushrod. This Firewall side pushrod has a small adjustment range that we normally use to make sure the Compensating Port stays open.
The booster-end of this pushrod is usually positively located in the control valve, and the other end, has the adjuster on it, and your job, during installation is to guide it into the socket, on the end of the M/C power-piston, to end up exactly the right length..
So since, IMO, your Chevy booster is ka-put, as is now becoming obvious by the hissing during pedal application; Yank it outta there, and get a Mopar one that is pre-engineered to fit your pedal. and get rid of the return spring. Mopar boosters have an internal spring that does the same job.
If the Chevy M/C does not bolt onto your Mopar booster, then get one that will.
The Mopar ones come in three sizes, namely 15/16th, 1 inch, and one and change ( I forget, maybe 1&1/32 or something). EACH smaller one will give a longer pedal travel, and be easier to apply.
The biggest one is harder to modulate, and takes more leg-power, and it takes a bit of getting used to.
I agree with @Garrett Ellison , the 15/16ths was my second choice over 20 years ago, and I liked it right from the start.
A New booster will NOT solve your pull to one side.
The pull could be:
a difference in the contact patches between the two sides, OR
a performance mismatch between the two w/c's, OR
a camber mismatch, OR
a strut problem.
You'll have to do a different diagnostic on that to find out which it is..
Here is a pic; notta Mopar, but you get the idea.
https://www.pinterest.com/pin/vacuum-brake-booster-construction--650770214894398633/
This pic shows the control valve, which I believe in yours is broken . The hissing you hear is vacuum from the engine side of the diaphragm finding it's way to atmosphere thru the broken valve.