Is the stock type transmission mount strong?

Been using the same OEM transmission mount 71 Dart for 10 yrs now....using a transbrake....ran some low 10s with a 360....But.....

this one is available for your transmission mount

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That's the new mount I put in. It just seems that the little 5/16" stud wouldn't secure it very well to the crossmember. The mount isn't even snug in the crossmember. The mount itself is secure to the transmission. It looks like the little stud is the only thing holding it in.