Like no exhaust install should go without RTV, cmon Jason.

I've used the clamps they give you...

OR, you can get better stepped band clamps, and then...if you don't have magic hands...they end up still being cheaper than a ZZP Downpipe.

Imagine that.

And it'll probably put down 10+WHP over a downpipe car with stock manifolds, because you still left the 2nd worst restriction in the exhaust system...the Front Manny.