I originally ran the 143 tooth flywheel & 11" clutch & the factory bellhousing was cast iron. Way-back-when there weren't a lot of performance 11" clutches available, so I switched to a 130 tooth flywheel and a 10-1/2" clutch, but the only bellhousing I could find for the smaller clutch was aluminum. The aluminum bellhousing cracked, was TIG welded, then cracked again (nitrous issue I think) + I like the toes on my right foot, so I upgraded to a Lakewood scattershield.

The Lakewoods will take either flywheel/clutch (offset arm for the smaller clutch comes with it). QuickTime (sp?) also has scattershields for Mopars and I think Lakewood recently bought that company. Anyway, at least for Lakewood, there is no advantage at all to getting a 2-piece scattershield. It "looks" like a nice inspection cover, but you have to unbolt the transmission anyway to open it. Even these scattershields can be destroyed by a nasty clutch explosion (ask me how I know) but they will contain all the flying pieces for safety. Looking back, I don't think I'd ever run another stock aluminum bellhousing, but it'd work fine on a "cruiser" car with no street/track racing.

And if you're trying to stay "stock", at least in 1970, the 383's got the 11" clutch and the 440/Hemi's got the 10-1/2". That always seemed odd to me since the larger clutch should hold better. And fyi - Centerforce clutches work great. My last Hays lasted 30 miles and one hard 1st-2nd shift. Don't let the diaphragm design throw you off...they're pretty darn strong. Just make sure to take out the over-center spring on the clutch pedal.