Must be in the compression bump ?

We're a few short on the hp, but 606 on the tq. using
stock compression, good heads, cam ecm, asm tb.

One more thing,
If he was breaking drives when stock, have him
check the u-joints in the driveshaft in the box to see if they're phased properly ( each end yoke running in the same plane)

Mine were 90* out of phase( which doesnt help
with driveline harmonics)

Chances are that the same person rigged my boat might
have done his since they're only a year apart.

He may have also done some intake work and a different throttle body. Again, don't know for sure but I know it is hard to hit 600HP in the 500 EFI's without some intake work.

He ordered his boat through GSC. He busted two drives in the first year. He said they found some alignment problem but that is all he told me. Again, he is not mechanically inclined so he had no idea what they found or did. Then the drives lasted a couple seasons until he blew the top cap off the port drive cruising about 45 MPH.

What else are you moving or removing? Once I got the batteries to the transom and all the trim and tab pumps as far back as possible, I ran out of weight to move back. I want to get more out of the cabin but once I yanked the fridge and microwave and converted the panels in the "bed" to aerospace panels I ran out of ideas. There are a few other things I am going to do with the cuddy seats but thats my last thing to do to remove weight.

Alignment problem ??....I bet we had the same issue.

I'm going to do the panels under the v berth, like you mentioned.

I'm thinking about adding weight ( like Bobby did) back
in the engine compartment, in the area outside of each
stringer, on the outside of the engines.

What I think that would be neat, is a bladder ( like wake
board boats use) that would fit down on each side of the
center stringer....that way, you keep the center of gravity
low.

I dont know how feasable that is though.

What I do know iis that sand bags or tractor weights on the
swim platform is out of the question, according to the mrs.:D

Do yourself a favor, take the stellings driveshafts out , rebuld them and have them balanced. Upon delivery, mine were out of phase too. I just put my engines back in, while they were out, I took the shafts to a driveshaft shop and had them balanced. First, always run them "in phase" second, dont let anyone tell you they are "too small" to be balanced. I dont think they are balanced from Stellings but I can tell you mine were WAY out of balance. The drivshaft guy said they were really bad. I suspect this is what set my knock sensor off when I first put the stellings boxes on my boat.

Driveshaft maint. is on my to do list.

I heard somewhere that Stellings has some kind of coupler like Merc that you can put on the fly wheel.
Anybody know if that is correct?

Do the driveshafts a flange coupling? Is that what you mean by running in the same plane...making sure the u-joint caps line up at the coupling? Sorry, never seen the inside of the boxes so trying to picture what you are talking about.

OK, found some pics of the boxes. I doubt when he said "alignment problem" that it was the carrier bearing inside the box. You would think that would just affect the ease in getting the drive to mount and the spline wear on the drive's driveshaft. The driveshaft from the box to the flywheel is a flanged coupling at both ends. So is the phasing you are talking about between the box driveshaft and the drive's driveshaft? I'm surprised Stelling's does not balance those driveshafts.

Yes, its called a "Drive Saver"

http://www.offshoreonly.com/forums/g...lings-box.html

Here is a link that comes up from time to time. They are $400 a piece and have a 4 week lead time. I opted out and decided not to use them (again) you are increasing the driveshaft angle to accommodate the drive saver since its about 1.25 inches thick.