Been all thru the B-max issues, yes the imco lower will work if 0 and -2 " if you angle drill for the water cooling passage.

Artic can you Pm me the trick for gear treatment ? need to stay @ 1.5 :1 so need too do something with lower gears even if I do go with the B Max or Imco SC
I'm looking into haveing heill cut gears made for the lower in town Here.

S.K.

nearly 200lbs for a B-max? Is that about twice the weight of a XR? how will that affect the transom assembly and bell housing etc?

You need to change out the vertical shaft in the lower to the larger Bmax one with coupler.

Lowers like the imco, and zr already have the larger verticle shaft. They will work with a B Max uppper.

I haven't had any problems....knock on wood....

715 hp last year, 830 hp this year, over 100 hrs... I don't beat the crap out of the boat...treat them nice and they'll treat you nice...

Lots of guys buy these drives and think they can drive it like it's a #6.... Case in point, the #6 has two verticle shafts and 4 gears in the lower to handle the torque.......

When I bougt my BMax drives I knew the lowers were the weak link but I never had any problems with lowers anyway, it was the XR uppers (IMCO Extreme SC) that I had issues with. If you buy any of these drives you will still need to take it easy on the sticks and you can't murder it with big power (900 hp like the other guy had) or you will find the next weak link....

Just my opinon but if you want to run 900 hp and run the piss out of the boat you need a #6 or a "full out Arneson" (not the bolt on extension box)....

When you get tired of repairing your broken drives, try konrads and they will last much longer than merc, imco, b-max and all the others

for $50k and a total re-rig I'll stick with my Bmax's, thanks!

Another 80 mile trip on the ocean today!

Let us guess, being that you are hijacking the thread.

Do you sell Konrads?

I think from the other thread we have read they are not the answer.

Too bad Konrad doesn't actually sell a drive that bolts in place of a bravo. Sure,you could totally re-rig your boat,add transmissions and boxes to house the transmissions,move your engines and spend 28,000$ per side,THEN a konrad will bolt right on.Of course it will blow up the upper faster then a B-max if your running serious tq though,Smitty

So it's possible to use my sportmaster lowers with B Max uppers?
Do I have to do any mods?

Dennis