As well as owning a Sprint I also own a 1981 T3 VW campervan, 2 years ago I did a Subaru engine conversion which involve changing all the fuel lines with suitable R9 rated rubber hoses.
There is alot of chat on VW forums about poor quality fuel hoses due to a few vans going up in flames. When I did the conversion I bought what I thought were the correct R9 rated hoses. The other day I was checking the oil & noticed that after only 2 years the hoses had started to perish badly.


I would suggest anyone who has used this type of hose check it out.
There is a company called Brickwerks who sell quality German made hoses, I have just swapped all the fuel lines, I am hoping these will last longer than 2 years.
Here's a picture of the Subaru engine installed in the camper, looks as if it was made for it.

Cheers
Tony