Nice ... those meaty tires look good on it. Golf's look the same from day one, but together they show their heritage. Very cool job! I have a love of these, from my wife's '77 to my present GTI.
The way I understand it, you could use those two Cummins inline 6 diesels, but they would have to be inline to each other, not side to side. Looks like a front end stretch! I'd love to see that.
That will serve you well. I have a D5100 that replaced my D80. I use a Tamron 90mm macro for model photos as Nikon only has 60mm or so and the Tamron has had very good reviews for a long time. I never got the kit with plastic lenses, but it's a good lens anyway.