The LM383,TDA200x chips were commonly found in a bridged (BTL) configuration in car stereo power boosters in the mid 70's to the mid 80's.
The TA7205AP was also used as well in brand names such as Kraco and Spark-o-Matic and a few others.
They used be a stocked item at radio shack for many years, but, they are quite dated now.
I used to have many of these amplifiers in Both versions.
Make sure that you have an adequate heatsink for the LM383 or TDA 200x as they do run a bit on the warm side.
They will handle a 4 ohm load in the BTL configuration as that was what they were designed for and was the only way to get any decent power out of them on an automotive voltage level of 12v to 14v.
They are a couple of my favorite chips of yesteryear and I still have a few of both in my parts bin.
jer