thats a nice box but they stick you with there steering that should be a option, when I put my 2''shortie on I picked 8mph with a carb change too went from bg 850 to nickerson 1050 I was happy. my x went from 7 1/2 to 5 1/2 I think or it was 7 to 5 ha hah. works good can't wait for the new power 1050hp

That box is 8000.00 without the steering as I already have Latham Steering on my boat, so this isn't a option..I'm going to check all my measurements first and see where I'm at. If its too high I'll put 1/2" spacers on it and see where I'm at there...I just don't want to loose speed in the process as this is another one of my problems the boat isn't running the speeds it should with HO's...Still have somemore prop testing to do in the spring as well.

Thanks for the replies.

Irish, I did all this over the summer on my 342. I went with Stellings which some love and some hate... But I wanted the adjustability. Either way, you have to buy new tops for your latham steering to keep your present rams. Then, becasue of the way they are connected, you need a new tie bar too $1600 when it is all said & done. You can always do IMCO and use shorties but I think shorties slow the boat down under 85 mph because they dont give enough bow lift like stock merc lowers. Also, the cost of 2 shorties takes the project up another $6000. FLEG is right though - 4.25 is the area you need to be for x dimention. FYI - If you go with the Stellings, PM me there are a half dozen things you need to be prepared for.

I had a 302 and extention boxes would do wonders for it... Heck, my 342 feels like a different boat.

Keith,
Did you get it dialed in yet ?

Did you change the X when you pot the HO's in? What is your current centerline? if it is around 7 to 8in - that is stock... If you werent blowing out with the Mags what has changed.

Yeah, finally - I might even go higher and/or try 5 blades...

It wasnt the boxes or the depth. The u-joints from the Stellings boxes were setting off the knock sensor and retarding my timing 20 degrees. I had the ECU's reprogrammed from Whipple to stage 2 and it slightly desensitized the knock sensors. Now it is at 76MPH and still some prop stuff to try. Took me 6 damn months to find that problem with 4 guys and the Merc computer.

I didn't change anything. It has always blown out I'm just trying to correct it for once.

There is a fine line between blow out and another 1/2 to 1 inch and you are decreasing top end. Try 5 blades from BBlades? Or let me know, I have a set of 1/2 inch spacers you can borrow for your current set up. The IMCO lowers slowed me down. Get some help from Smitty, Fleg and Jay Tee. They all had great ideas and knew their stuff when I was fooling with Baja ext boxes. Start now, it takes a couple months of fooling around to dial it in...

I've got the setup for you! -3" Drives on neutral IMCO boxes, 380 tabs & 4 blade wheels.

Running stock 496HO power???