OMC 800 outdrive. Alpha 1, Alpha 2 or What?

Old 24' Cruiser (Bayliner #BLB633NSO573-3E). I believe the year is 1973 (does the serial number also tell me the boat Model?). It has a 350 Chev, attached to an 800 series OMC leg, with mechanical shift cables.
I am told it could be a "hydro boost" or "straight pin" mechanical shift.

1) Is this Alpha 1, Alpha 2 or something different?

2) How can I tell the difference and is there really any post installation performance difference when shifting?

google image search is the easiest ID tool. Or post a pic here.

Any OMC stringer drive will look similar to this one.

That drive looks like it is one of the electric shift ones, my neighbor has one on his boat.
Does yours have 2 wires or 2 cables that come through the transom?

My 800 has a different housing, top cap and no square exhaust port. The top cap says "OMC 800". It is a mechanical shift (two thin cables in a sleeve, that look like your old pedal bike cable brakes with anchors).

Apparently there are two types of mechanical shift. Older being "hydro boost" with an oil pump, in the nose cone of the lower leg to assist the shifting.
Newer being "straight pin", with some associated electrical switch in the control unit.

I was trying to determine how to tell the difference (if there is one) without gutting the lower leg.

5054d said:

I was trying to determine how to tell the difference (if there is one) without gutting the lower leg.

Click to expand...

full mech lower has a rectangular zinc anode behind the 6 idle relief holes

hydromech has no rectangular zinc there

One zinc anode.
Opened up old damaged one (reef at full speed)
Straight rod down to the nose cone.
Thanks again.