awesome 21 turbo

im a member on the rtoc so could ask around if stem seals are an easy or awkward job.
would love drop a 21 turbo engine in my 5gtt but it would have go in the back and tbh i dont want a super noisy car inside lol
what spec is your engine fella ? i know there is a guy selling a gt28rs turbo over on the rtoc for £400, would make a cracking turbo for the 21