Most people typically install the bellhousing over the clutch assembly and then install the transmission. Since we're assembling the engine and transmission outside the car, it is not a problem to mount the bellhousing to the transmission first. Our TKO-600 requires a bellhousing with the proper bolt pattern (a stock T5 bellhousing will not work). While there are several SFI-approved bellhousings, they are quite tight in the Roadster chassis and require modification. We chose the Tremec aluminum bellhousing, which is machined to closer tolerances and does not need to be indexed. We got ours through Dallas Mustang (PN 8393; $199.95). If you want the safety of an SFI housing, you can use a safety blanket around it.