Trade: 901/07 alu for 901/03 alu

I would like to trade my 901/07 aluminium engine case #3180163 (911L sporto) for a 901/03 aluminium engine case 208xxxx. (911T)

model year 68.

Attachment 596668
Attachment 596669
Attachment 596670
Attachment 596671
Attachment 596672

Thanks

what is the difference? both are non matching to the car right?

Yes, I have a chassis 2.0T 68 serie A, I convert to T/R specifications, so engine 901/07 is not correct. Looking for an engine case 901/03 or 901/02. I have located a 901/03 but it is in magnesium for serie B. I prefer aluminium.