A search of the forum shows 29506337 and 29558329 for FT of similar vintage to mine. I suspect that the difference might be the 4"' versus 6" sump. To add to my confusion, I have seen the 29558329 listed for 4" AND 6" sump.<br/><br/>Did FT use 4" and 6" sump transmissions? If so, how do I determine which I have? I didn't find a good explanation of how to tell one from the...