So I've decided to replace the whole ac system since it hasn't worked since '92. Today I installed new compressor, condenser, hoses and am putting on the evaporator, low pressure switch and orifice tube tomorrow. My car doesn't have the high pressure switch/adapter hose. Just wondering if it's ok not to have it or if I should add it. Its been so long I honestly can't remember if my car had it or not. (2823) Also, I saw a video recommending using Red Tek instead of 134a. Anyone have any thoughts on that?

Thanks for any help/advice!!