Why replace a heater-a/c box that works fine? new style compressor? Sure, but the original evaporator works fine & you have the option of fresh air which is very helpful if your windows fog up in the winter.... The new systems block the fresh air connection.. I'm running the stock evaporator, stock condenser, stock blower fan with added relays so it actually moves a decent amount of air... I'm running a Sanden Compressor with the Bouchlion brackets... I used the stock liquid line, a OE style receiver dryer, I used the formed metal portions of stock suction & discharge hoses... Finished the system up three weeks ago, the temp locally has been 100-106 & I'm reading 47 degrees at my center duct....