TRS to SSM3A

[StraightJacket]

Stellings make the boxes, like I said I'm not sure how it will affect your Gun , but I can say I have rarely seen them. The adjustment is like 3 inches.

[DAREDEVIL]

The adjustable boxes you're talking about have how much adjustment? And who makes them?

The boxes for the SSM 3-5 are all adjustable ,,max +1 inch.

Then u would need driveline trannys and driveshafts. for each 10 inches back u need to go 1 inch up,,,with #3 a's i recoment go as high as u can .
Also no need to fill anything, just cut out and re-drill .
Boxes will make it run like its 2 feet longer,,,i do think u should stick #5's on the boxes togh butu will have to sacrifice around the dock and in getting on plane time with #5's.
Take a look @ this ,,real numbers.

[DAREDEVIL]

Stellings make the boxes, like I said I'm not sure how it will affect your Gun , but I can say I have rarely seen them. The adjustment is like 3 inches.

In your pic,,,#4's on boxes.

the adjustment for merc or stelling boxes ( only ones ever made for 3-5 )
is -1, neutral ,or +1 inch.

[DAREDEVIL]

The ideal drivehight for a SSM ,or better a surface drive prop is flush with the bottom of the boat ( propshaft ).

Therefor with the 3a's u never get there ,so i would say NO boxes.
since u have a notched transom ,,,that is already your box !!!!!!
U also dont want to change your engine hight because of the balance of the boat,,,so u will be around 1 inch higher then u are now with the TRS ,,it will help,,but i would go look for a set of #4's or 5's with a 1 inch spacer they be just fine ,,or then wih boxes and no spacer !!!!!!!

The props u should get are 17 X 27 to start,,maybe 28's with 750 each side.
side by side engine likes diameter,,so don't go below 17 inch !!!!!

BEEN THERE ,DONE THIS, ok ok ..still do this .LOL

PS.: need anything or help,,,let me know.
Scott

[Ratickle]

Is the transom assembly the same on a 3A and a 5? I already have 3A's on the Black Thunder.

[MikeyFIN]

To my knowledge YES.

[dockrocker]

You may want to talk to Dave Dahl aka DJD. He did this swap on his flat deck and can give you LOTS of info on the drive height.

And I believe DJD's old flat deck is now owned by Crazyhorse, who is also a west Michigan native (or was, last time I looked).

[DAREDEVIL]

Is the transom assembly the same on a 3A and a 5? I already have 3A's on the Black Thunder.

Not really ,,but they fit. The #5 gimbal is a little more staudy. But same pattern for studs and oiler.
In the first pic, next to the Merc boxes u can see the surface of a #5 gimbal. The 2nd pic shows a #3 gimbal ( its a lighter bellhousing with support ribbs ) .

LIKE I SAID,, I HAVE ALOT OF STUFF !!! LOL

[Ratickle]

So a 4 or 5 leg will not bolt on to a 3A transom assembly. Is the 3A and 3 transom assembly identical?

[DAREDEVIL]

So a 4 or 5 leg will not bolt on to a 3A transom assembly. Is the 3A and 3 transom assembly identical?

Yes they do,,,,,its the same boltpattern a 3a is basicley a #5 in a #3 housing and the #4 is a #3 in a #5 housing ( the bottom housing is a diffrent part but looks the same and they all have the same boltpattern ) the down shaft on a #4 (newer) is a polygon shaft which is stronger then the #3 shaft.
Ratings : #3 & #4 700 HP , #3a & #5 750 HP.

But those are old ratings from merc since they only had the HP 800 as the biggest engine back then,which dynoed @ 700 + HP and 800 FPT !!!
The HP means Highperformance infront of the 800 ,not horsepower like some people think.

The #4 big shaft also uses the #5 prop shaft and the reg. #4 has the #3 prop shaft. ( 26 and 19 spline ,,26 same as #6 spline but diffrent shaft )

Hope that clears it up. LOL

[baronmarine]

The ideal drivehight for a SSM ,or better a surface drive prop is flush with the bottom of the boat ( propshaft ).

Therefor with the 3a's u never get there ,so i would say NO boxes.
since u have a notched transom ,,,that is already your box !!!!!!
U also dont want to change your engine hight because of the balance of the boat,,,so u will be around 1 inch higher then u are now with the TRS ,,it will help,,but i would go look for a set of #4's or 5's with a 1 inch spacer they be just fine ,,or then wih boxes and no spacer !!!!!!!

The props u should get are 17 X 27 to start,,maybe 28's with 750 each side.
side by side engine likes diameter,,so don't go below 17 inch !!!!!

BEEN THERE ,DONE THIS, ok ok ..still do this .LOL

PS.: need anything or help,,,let me know.
Scott

thankyou for all in info scott. it's been a big help. i'm going to stick with the 3a's.

todd

[DAREDEVIL]

thankyou for all in info scott. it's been a big help. i'm going to stick with the 3a's.

todd

And u be just fine with 3 a's ,,latter u can just swap them out to 4's or 5's if needed or wanted.

Any guestions,,pm me.
Scott


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