Bottling a Strong Golden Belgian, Bottle Question

I'm planning on bottling this ale tomorrow and would like to bring it to 3.5 volumes of CO2, which calculaltes out to 7.2 oz of dextrose. I've used 6 oz in my Sam Adams bottles (which I normally use) and have had no problems but don't know if they are made to tolerate the additional 1.2 oz.

I have some "old returnable" Busch bottles that are definitely heavier; 10.2 oz for the Busch bottles v.s. 7.5 oz for the Sammys. Anyone know if the returnables are overkill for this amount of priming sugar? The reason I'm asking is I would need to dig them out of the storage shed and clean them up if I need to use them...and it's darn cold here right now.

Thanks in advance...

Most bottles are stronger than they "need" to be... I wouldn't worry too much. Then again, if you've used them multiple times they can start to weaken (I've heard) no matter what pressure they were originally rated for.