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350 and gear box engine stand


Does anyone have any measurements for a 350 to gear box engine stand mainly the top part of it, I need to modify my rigging which is setup for a 540 and I need a good idea of how much modification I need to do or if I just should buy new rigging


Well-known member
I'm afraid I don't have the dimensions you are asking for, but will share a couple generic observations that you may find useful.
There is an option to split the difference between the two extremes of scabbing together a modified engine stand and building entirely new rigging. That would be to build a new engine stand and then scab your existing rigging to the front of it, if possible.

You haven't said what material or how old the existing rigging is or made any reference to your budget. These are both more than passively relevant parameters. If it's 20 yr old conduit, likely best to build new all around. If it's only year old stainless steel, then that may represent a whole different consideration.

IMO (which is admittedly worth no more than you paid for it), rebuilding/modifying an engine stand lends itself better to an engine swap involving a DD (or w/a gearbox) and less to switching between DD and geared. With what you propose, you will generally end up with shorter back legs than front legs, and the distance fore and aft will likely need extended as well. This doesn't mean that it can't be done, but the more the mods needed, the more weight is gained. The more weight gained, the less the difference you will you will see, given the effort. It goes without saying that both Aesthetics and Safety issues are yours to weigh, but by far, most would agree that new is better.

Perhaps the more important considerations are that:
a) the engine's vertical center line will sit lower (compared to the prop hub) with a gearbox than DD, and
b) you would be presumably be going to a larger diameter prop so may want/need to reposition the prop hub in relation to the bottom of the hull to maximize your thrust.
Both are easy to achieve building a new stand; both are mitigating factors when modifying an old one.

Generally, pics are a big help. That may not be the case in this instance, but most of us are at least passively curious as to what you have and are working on. There is a lot of help here to be had; you've come to the right place.
Adding your location to your User Profile could/would also benefit you, as someone with your "then needed insight" might be local to you.


the stand is made out of some pretty nice stainless, I planned to chop off the existing mounts and kinda build a frame for the gear box and engine and then figure out my position up and down of the hub


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Well-known member
Understood. Can you post a picture of the side view of the rigging?
I only ever had the need to modify an O-540 stand for a geared CM once, and opted to go the other route.
Am curious how what you have compares to what I had. It was a Dynofocal mount as well.

I would only suggest that you alter your sequence of events, ie. Calculate your desired hub height first, then figure out your 'framework' to best accommodate as much of your existing stand as possible on the front side. I have yet to figure out a good way to uncut anything. :wink: