Are the hydraulic pumps for k-plane 280/380s the same oildyne pumps as those connected to alpha/bravo sterndrives (can they be used interchangeably?) And what are the k-plane internal hose fittings (same as those that connect drive trim pump, or totally different?)

you can use the same pump/motor on the k-planes that you use on the drives i have done this on my boat it will make the k-planes about twice as fast as they were(which i like). i belive the fittings are the same size.

Thanks very much - greatly appreciate the info.

It's my understanding that there are 2 different versions of the trim pumps. Newer and HP styles are easily different. Tab pumps hang on bulkhead brackets an dgenerally smaller. Older styles looked the same. There are high pressure/low volume for tabs and low pressure/high volume for drives. They are interchangeable however using the high pressure low volume on drives will cause them to barely operate. Just what I've heard.

tab pumps and drive pumps (new style )look the same difference is in the valve body.

I would like to know if it is completely different valve bodies or are there screw in orifices to modify the pressure?

I have a pair of good used drive pumps available, cheap.

not to jack your thread but quick question for the local plane experts, I just bought eddie marines and looks like im going to have to mount the pumps to the transom, How do you guys recc mounting the pumps in that sitiuation>? Through bolt and make a bracket on the outside>? Seems to be the best i can come up with. I just dont want to trash my transom

i would not thru bolt the brackets find some 1/4 ss lag bolts and do it that way just my 02 cents worth.

Do the eddie marine or dana marine use the low pressure/high volume valves stocki? I've seen at least one post that comments that either the eddie or dana marine tabs operate quicker than kplanes.

By using the high volume/low pressure on a k-plane, other than the danger of the tab going down too quickly and presenting a danger from easier driver error, are there any other downsides? I think I'd like the faster operation as I'm thinking of mounting these on a 60 mph boat and will likely have them all the way up from 40 mph up. I'd like to drop them to get on plane. In my last boat I had a pair of the benette sport tabs (twin cylinder sharing the single benette pump) and I found those tabs to operate much too slowly for my liking - I would put them somewhat down to get up on plane, but then they would come up so slowly that I'd end up too bow-down so I had to balance that by not putting them down as far as I wanted to so I could get them up in time.

But (forgive my stupidity) changing from low volume/high pressure to high volume/low pressure, is there any problem introduced by not having the "high pressure" with the k-planes by using drive pumps?