I am putting together a 548 bbc engine and will be running a bravo xr with a sportmaster The engine will most likely later be running a supercharger next spring I don't know what drive coupler is supposed to be used. I see there are like 4 different ones.Anybody able to steer me in right direction. Picture and part # would be great. Thanks for any info.

I would use the steel splined one. It comes in standard or with a long snout.

All the Merc part numbers are listed here
http://www.mercruiserparts.com/bam/s...1368/10772/130

Thank's for info Griff.

http://www.ebay.com/itm/New-OEM-MerC...lp6YMg&vxp=mtr

Thanks 33outlawsst. Any mods if you use long snout? Do they both use same bell housing and CV joint and spilne?

no mod's, just a little tighter getting it in the inner transom assembly, just go in at a little angle down in the back and you'll be fine.