I think that back then there were two versions of the B1, a magnum and standard. The magnum came behind the 454 and 502 mag motors, the standard behind the 330/310 and small blocks. This is probably the latter.

Ok I found that I have stored thru Mercruiser The Bravo history book that tells everything straight about their Bravo products from the start in 1988 thru 2005.

Bravo 1 for 1988 and 1989 - the 2 gear oil reservoirs was an add on and the easy add on to connect was to mount / screw the oil line into the vent hole plug in the upper. For 1988 and 1989 they had NO gear lube passages in the driveshaft housing or the bell housing. They had oil dip stick in the upper top cap. They drained the gear oil front lower bullet.

1990 here is where I was talking about the hydro dynamics of it. - 1990 "bravo 1 received streamline gearcase - strut moved forward 2 inches" this offered better hydo dynamics.
1990- Bravo 1 drain plug was now in the rear of the propshaft carrier this new carrier is called C2 carrier - Mercruiser terms
1990 Bravo 1 gear lube was added along with the correct oil passages thru the driveshaft housings and transom assemblies.
1990 bravo 1 dipstick totally removed from the top cap cover in the upper.

If I had to say - the 1993 bravo outdrive was probable the strongest OEM STOCK OUT OF THE BOX outdrive made by them.FWIW.

I am glad I found this Bravo history info thru mercruiser stored on my puter. I would not have looked if it wasn't for your post.

Bup you da man! Heres a rookie bravo question all bravo lowers will bolt to 1989 bravo 1 upper correct?
As far as hydrodynamics i was thinking bobs machine bigfoot cone, any thoughts anybody.
If you think you are glad you found this i bet there are many others including me you did as well.
Thank you

Will my x dim change going from alpha to bravo?

These early models did not have the plastic wear plates. Check to see if the gimbal ring has rubbed the housing. I just repaired them on both my drives. Takes a lot of time welding and grinding.

1bigjim, not sure what you mean. Please explane.
Thanks

1995 Bravo units added the plastic thrust wear pads on the sides of the outdrive. These plastic wear pads helped the inner gimbal ring portion from wearing and or wear grooves in the lower inner ear portion of the gimbal ring.

Plastic pads much like the alpha's use. This drive is comming from light weight boat 454/330 driven fairley easy, i'm guessing.
Anybody know about any propshaft heigth diff. Upgrading from alpha to bravo?

BUP, REGARDING THE REZ HERE IS WHAT THE GUY WROTE TO ME " Gearlube monitor exterior oil line will need to be replaced (leaking). " DOES THAT HELP YOU DATE THE DRIVE?

sounds like a 1988 or 1989 as he says exterior line leaking. It would be my guess as I do not have my eyes on it nor any HIN or serial #'s to validate year.