If the charge hose is different than your setup, simply buy a dual size valve piercing style can tap. Worse comes to worse, and you dont want to go that route, you can charge through the high side, but cheezy solution. Buy the can tap with 2 size fittings. That way it will work with the HF gauges. Also, you still need the high side adapter if doing some domestic R12 systems...

Many people on Aircondition.com suggest the newer Side Tappers ...
but everyone has to be careful visualizing what you are getting from the can... you want vapor... so relative to the earth.... you need to take from HIGH .... if you stick liquid into the system near the compressor you break the valves...

On the very old compressors, this was true. I've been doing it over 25 years. Never ruined a set of reed valves yet charging liquid. Chances are that if charging liquid does one in, it's on it's last legs anyway. But if you want to, just pierce the bottom of the can with a side tapper, and hold it upside down to charge gas.

Something like this...

I ruined two new compressors that way in one day... in the mid 1970's....
The parts house was really unhappy....

Liquid can be put in safely... but when dealing with the WIDE variety of experience on a forum... safer to suggest the slower vapor only method....
People should not be punished due to being slow or untrained...

Yep, I believe it almost 40 years back... Be careful not to overcharge as well obviously. Depending on the refrigerant you use, that WILL lock it up QUICK.

We preach not overcharging around here....

Also, I re-read my original reply. I didnt mean to charge through the high side on the car obviously. But in a jam if the HF charge hose wont fit, you can vac and charge through the high side of the HF manifold, with the low side connected properly to the car. But better off getting the proper can tap to match the hose if you have time.

About that same time I did hook up a can to the high side....
was lucky I felt of it... it was getting HOT instead of chilling as it was supposed to... was lucky it did not explode in my face...as it was hanging from the underside of the raised hood... very serious .... makes my knees thinking about it ever since...

Yes, very fortunate it was the first can in an empty system.