Imco 3" Extension Box
 

Curious if you have to reglass transom or if the inner and outer assemblies go in stock location? I know everyones thougths on center of gravity but with the 3" extension box I will have the same x and cog as the newer ones.

This is a direct replacement although you do know you have to raise your engine when doing this correct? They're box has the -3" raised built into it in order to have your alignment right you'll have to raise the motor accordingly. If you wanted to glass in the transom go with a neutral box. Then just raise everything.

if your talking about the 12" standoff box with the 3" rise, Irishtornado is correct, everything will bolt right up, but you have to raise the engine 3" to match the standoff box.

Yea Im aware of raising the engine just curious if the transom needed to be reglassed. Thanks

My understandind is you can also use the Stellings adjustable box in the neutral position without raising the engines but even with that it raises the "X" 3/4"-7/8".

All I hear about the stellings is the possible drive damage.... I really dont need 'more' drive problems

Have you talked to anybody that has Stellings boxes??????

I do. My boat is a 1997 and has almost 500hrs with them. Originally it had 750hp blower motors for the first 100hrs. It has had 502mpi's since then. The drives are the original 1.36's and have not had a failure.

That's what I asked him in a pm. I haven't heard any Neg issues about Stellings boxes either. I'm installing them this season for the first time and would like to know of any problem if any so I know what to look for developing. I'm gonna try the neutral position first with -2 Imcos from std. Bravo 1's and no boxes so it should be quite a difference. Sorry to hi jack the thread a little. I would like to hear of any prolems period on extension boxes.

The issue is that with Stellings, you don't use a regular drive coupler to absorb any hard shocks from air time and a missed pull back on the throttle. Stellings does make a "drive saver" that can be used. I do not have drive savers on my boat.

I see. I'll be using a set of driveline bellhousings with a pair of Bravo couplers and then shafts back to the drives. We of course had to move the engines forward about a foot and a half and use a rear engine plate for mounting so this shouldn't be an issue. I had heard the solid hub was hard on drives. I think that problem we have solved, Thanks Griff.

I have got over 200 hrs on my IMCO standoff box with the torision bar shaft and have had zero problems. for the last 30 hrs it's been pushing about 1100 hp.

Is there any vibrations with the stellings? Also what maintenance is required

No vibrations that I've noticed. Maintenance is just pulling off the side covers every 30 hrs or so and greasing a few zerks.

Actually, my engines are moved forward a foot and I have a short driveshaft. No coupler though. It was set up this way originally when built. They could have and it probably would have been better doing it your way with the coupler.

I would have just used the solid flange and the short slide shaft supplied with the boxes but since I had the driveline stuff sitting on the shelf and the couplers left from the Bravo drives I figured that it might be a smoother easier load on the drives. I had heard that shifting into gear was a little hard if the rpm's where up a bit. As for any vibrations from the Stellings? The only thing that would cause a vibration with using a box would be either a misalignment of the shafts or a joint going bad which could happen with any box or installation. I have delt with Stellings service and I am very happy with their service, advice and knowledge of their equuipment. I decided to replace all the seals and bearings in the carriers before I install the boxes since I bought them used. I also went with their beauty inner rings which have no rear mounts or inner steering provisions, rather than use the bravo inner plates and cut them to clear the shafts.