Okay here's the story.
Bought the boat, Alpha-1 MR, 4.3 GM, blown motor.
Repowered by marinizing a 4.3 vortec, didn't align my motor, blew my coupler after about 20 hours of use. (altho the boat ran great)
Replaced coupler, in the process converted from the round style to the triangular style. Also replaced the spline shaft, u-joints, gimbal bearing, as well as the rear motor mounts (bellhousing that bolts on the back of the engine)
Now that it's all back together, I have a slight knocking sound (in gear or neutral) when I turn 100% left or 100% right. I can go to 90% and not hear a thing. Other than that, the boat runs fine.
I even removed the leg yesterday and verified the alignment, it's bang on (grease the same on the bottom of the align tool as the top) While it was apart, I examined the ujoints and spline shaft for any sign of wear, hoping it would reveal where the knocking sound is comming from, but it all looked fine.
So my question is. Why am I getting this knocking? I know a lot of you will not approve of me retrofitting the new coupler in, but, now, it's done.
I do still have my old spline shaft, which apears to be in good shape. so if it will solve the problem, I could go back to the old shaft.
In case anyone askes, here are some other new parts:
shift shaft seal
Already mentioned up top:
coupler (old style was round, new style is triangular)
rear motor mounts (rear engine bellhousing)
Everything has been greased with the appropriate grease, etc etc