Narrow R129 rear end or use C280 rear ?

[97 SL320]

For my R129 SL track day car, I'm resisting adding fender flares to the rear, front might need altered a bit.

Take off Pirelli World Challenge slicks seem to be available but won't work so well on 9" wheels. ( see sizes below )

So, when checking rear track widths I've found the 95 to 00 C class W202 is 57.6 In 1464 MM / 90 - 01 R129 SL 60.0 In 1528 mm The 2.6" difference would keep the tires under the wheel wells. This is comparing cars with the same wheel offset.

I know the hub carriers are the same between W202 and R129.
I'm pretty sure the lower control arm and other bits are the same as well.

So the question is, has anyone gone down the path of using a W202 sub frame in a R129 or narrowing a R129 sub? ( or a similar swap ) This isn't a question of can I do it and more of a can I save some steps. Car is getting gutted , caged so doing more welding isn't an issue.

In any event I'm leaning to using a aluminum case 8.8 Ford center section from a Explorer so axle lengths will need to be altered no mater what I do. The 8.8 offers many ratios and limited slip as well. Also, doing work for a scrap metal yard allows me to get parts for scrap price.

Thanks

Fronts are 275/645-18's(275/30-18), 10 - 11.5 wide wheel
Product Code: 2128700
Compound: DH
Size: 275/645R18
Measuring Rim: 11
Rim Width Range: 10.0-11.5
OD (inches): 25
SW (inches): 11.7
TW (inches): 10.0
Rev (Rev/Mile): 796


rears are 305/645-18's( 305/30-18)
Product Code: 2128300
Compound: DH
Size: 305/645-18
Measuring Rim: 11.5
Rim Width Range: 10.0-12.0
OD (inches): 25.5
SW (inches): 12.3
TW (inches): 11.8
Rev (Rev/Mile): 800