have a 98 powerquest with a 454 mpi bravo 1 outdrive...get a vibration after getting on plane...I can get the vibration to go away with adjusting the outdrive trim...im leaning towards u joints?...just bought the boat last year so I don't really know its history...what do you guys think?..thanks in advance...

Pull your outdrive and check u joints and gimble first

Any dings in the prop ?? It don't take much to cause a nasty vibration . Being the vibe goes away with trim i would also suspect u-joints . While the drive is off check your engine alignment with the tool as misalignment can cause bad things to happen to your coupler and gimble bearing . I hope this is helpful .

thanks for the suggestions everyone...two more questions...anyone have a part number for the u joints and where would be the best place to order a set from?...thanks again..

the u-joints are Dodge 72 318 engine auto trans full size car. pick up challenger dart are probably all the same.

1972 Dodge Challenger / Dart, etc 318 engine lists two different bearing cup diameters (1.078 and 1.126) and cross widths. They also have the grease zerk in the wrong location (will hit the yoke), but the non-greaseable would probably work if you get the right size.

I personally like to be able to grease mine...just piece of mind I guess

forget about u joints from a dodge,get the merc ones from any merc dealer.

I think that's probably my best bet to stay with actual merc u joints...I know you can get other ones to fit...but with my luck something will go wrong and I don't wanna have to do this twice...anyone have a part number for the merc u joints?...hate to go to the local boat store and pay twice what there worth...

better to buy the right one first,but if you decide to get the ones for a 72 dodge,you can put them on ebay when u find out they wont work,or put them on your 72 dodge truck,