w201 r12 to 134a coversion

[aqua190]

when i bought the car, somone had already done a coversion, the quality of which i didn't know. i had a leaking hose, so i took the opportunity to do it right. repl compressor (rebuilt), expansion valve, rec-drier, both switches on rec-drier, temp sensor on block, heater control valve (looked fine once i had it out). flushed entire system (not much debris, some dye though) and thoroughly cleaned condensor (not very dirty).

on hwy, can get 40 deg f from center vents, at idle, more like 50. so, i have researched the forum and have come to the conclusion that the only way to pull the temp down is to repl the condensor with a larger, parallel flow unit. my question is, has anyone done this, and if so what is the maximum size you can fit in without too much modification. i know i will have to have some connectors fabricated (no a big problem), and evac, rechg the system again but that's not a problem either since my neighbor is an a/c tech.

91 190e, 2.6
91,000 mi

thanks