Easier than slant to V8.
Hunt down the early A slant 6 motor mounts/brackets.
The early A transmission crossmember will work fine with the later 904 trans.
The later oil pan *should* fit fine and have clearance, since you have a drop center V8 centerlink in the car already. The special pan was to provide clearance to the flatter slant 6 centerlink, so you may be okay in that regard.
