flex pipe

OK, so I'm getting ready to install a mk2 manifold/down pipe on my 84 mk1 GTI. I'm a little concerned that this setup won't have enough flex and will end up cracking the manifold. Has anyone done this before and will it be good enough or should I put one of those braided flex thingys in there as well?

Here's a pic of a similar downpipe/flex pipe…

fs* Twin Down Pipe and Flex Pipe $50/obo in MA | VW Vortex - Volkswagen Forum

Thanks

buy one of the slip on/weld on jobs off ebay. loads of them about and it's what i plan to do with mine to stop it rattling and hitting the floor so much!  they're only about a tenner

Jon.