Transmission tail seal

[Steveandtheboys 0]

I can not find the same seal that I pulled out of my 69 mustang transmission. The od is 2.506 ID is 1.69 with the depth being .5

i find the same Id and od but at only .3 depth. Will this work? All auto store have been zero help. 
 

I have the 351 Cleveland motor if that helps anyone. 
 

if anyone can point me to a place that may help me find a seal that would be great. 

[jmlay 80]

All of the below match the specifications of your original:

National 7300s

National 7296s

National 5203