I have almost 900HP and 875torque to the 3a the fluid is perfect every year. No metal on the plugs. Straight bottom Gun

I had 750's on 3's in my cig. The only problem I had was oil expanding when warm and leaking out, then starving the top gears for oil. Put in 2 expansion bottles and that was cured. Never broke anything else again.

what kinda speed you getting out of your gun? sound like a nice set up

whats the diff between 5s and 3a's the length?

dont the upper gears ever fail, or they still avail from merc? thx, rm

The 3a's are approx 5 1/2 inches longer than a No 5 drive .
RG.

so they have the same shafts and gears in them? thx, rm

6" actually 18.311 for 5's 24.311 for 3's and 3a's

The x dimension was moved twice on my Top Gun at TNT by glassing the transom. The 3As on mine run at the same level as 5s. Good setup 1:68 ratio, awesome acceleration and punch

I have new upper gears for both the #3A and #5 (they are the same gear), in a 1.31:1 ratio combined with the 1.125:1 lower makes a 1.48:1 overall ratio drive. These gears are NLA from Mercury. I also mfg. and stock new LH and RH lower gear sets and propshafts for the #3A and #5 and supply new 1.75" dia. propshafts for the #3 and #4 drives. In my opinion the #3 SSM is a great drive but the #3A is much better. Same dimensions as the #3 but much stronger.

If you ever need replacement upper gears for your 1.68 #3A's I have 2 sets and there doesn't seem to be any more around.