Just talked with TA performance on this. The one I got, TA 1806 is the one that is recommend on their site for our car. But when lowered (I have SR perf springs), it seems 1806B is the better choice since it is super low profile.
After my call, they will update their website to suggest this. As for me. don't want to spend money and install time on this twice. Gonna try making a relief with a bat to bend some space for the gas vent pipe. The pipe is tied to plastic pipe and wont let me relocate it without cutting it and getting creative. If I need to, I will do that if a relief does not work.
I love their products and had not issues with my fox bodies. I guess I need to get creative in this case to keep it. Oh well...
Hopefully this gives a heads up to the next guy. Check with them first, but likely want to buy the 1806B.