A friend of mine has a 461 with a 177 blower sitting on top of it with a 1050 Dominator carb. on it.I think the 1050 is much carb for this size motor. What do you guys think would be the best size carb for this set up??

I wouldn't go any smaller, merc used a 1050 on the 525 sc. A 454 with a 177 blower. It's pretty hard to over carb a blower motor

The 1050 will work fine It was used on the 525SC. Start with 96 jets all around and 6.5PV's.