" PLEASE be precise, if I buy, there's no way back!
"
That's alot of pressure.
You didn't mention what year is youre car. But, in general with the 87+ aluminum arms you will have too much offset increase to fit those wheels under stock fenders. With an early 944NA setup, and those 15x6's, you car just fit with the wheel in the back with a conservative tire choice. In the front, do the standard 2 or 3" narrow beam, and you're fine. The wheels should clear the calipers, there may be some small 'spacing' required to insure the spokes don't foul the calipers. I'm not sure how the replica wheels are cast. BTW, there is a place in the UK making those wheels.
Use a 944MC.
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