Installing a 200-4R in a GS

by Jimmy Williams

On the way home one day, I was passed on the highway by a group of Grand Nationals and a number of street rods. I wondered what it would take to put an overdrive transmission in my 1972 GS. First of all, would it hold up to the torque and would it last if I drag raced it on occasion? Second, would one bolt up to my Buick block bolt pattern? At that point, I did not have the slightest idea if it would work. However, I knew if it was possible, I would do it.

Several weeks passed and the idea of an overdrive transmission faded. Then I heard Art Carr said that his 200-4R transmission will hold up to the Buick 455's torque. So, I called Art at 714-962-6655 and asked him some questions about my application. I ordered on of his 200-4R and installed it.

There is no exact kit that works for the Buick 455. There were a few tricky pieces and some exact specs to adhere to as follows:


The great thing about the new trans is the first and second gears are a little steeper than the TH400. Third gear is the same but overdrive is 0.67! Since I have a 3.42 rear, that computes to a 2.29 on the highway. The car is much quieter and gets better mpg. First gear for the 200 is 2.74 vs 2.48 and second gear is 1.57 vs 1.48.

If you have any questions, call Jimmy at 803-783-7659 eves.