am replacing my blackpipe to the ceiling. going to single wall from double. have plenty of clearance. in a garage. question is this. bought the pipe today and the tee for the stove. 6 inch. stove has adapter on back that tapers to crimped male end. o.d. is exactly 6 inches and the tee o.d. is the same..didn't realize that the double wall pipes o.d. was approx. 6.5. what does this require? the crimped end of the adapter needs to be slightly smaller than the 6 inch o.d. of the tee..will I need to crimp it further? or do I need another adapter?