The Mk 1 axles are shorter..
Wheels;I have two E 30 BMWs. The 91 has 14x6x30et( 318IS)
The 84 has 14x6x35et (318)
The E21 has 13x5.5 x18et (77 320i)
Our Miata has 15x7 by38et.
Stock 14in VW is usually 14x6x38et. ( 85 Mk 2 and earlyMk 3)
Less et # equals the wheel further away from center of the car.
BMW wheels have been my choice for 15years. Thanks John....