I am restoring a 1979 Monza 24. Replacing the small block/alpha with 510BBC/Bravo. I understand that the Bravo is longer than the Alpha and thus I should raise the drive heighth. Any thoughts on the drive heighth? The boat is similar to a 24 Pantera.

Thanks

17.5 works great on that style hull,did a few old style 24 excalibers and they ran great

mine was about 17.25-.5 according to Jo.
JC felt my boat could have still used a shorty too.

How long is a Bravo, 22 or 23 inches CL to CL? I always get the X thing wrong...
Anyway, my 1997 24' Super has the prop shaft about 5" below the bottom.
I would not mount the drive any higher than to have the prop shaft at 4" below unless you plan to run some high $$ 5 or 6 blade prop.
There is a fellow I run with on occasion that rerigged a 24' Condor to 3-1/2" or so below and needs a spacer.
One other thing to consider is to keep the engine as low in the boat as possible for a good CG.
Maybe go with a short drive if you want with a higher prop shaft.

thanks for all the info....I thought about the CG issue and keeping the engine low....maybe I'll need a shortie lower unit

Yep, 17.75 max do not get too greedy with the X. 17 to 17.75 seems to be the best. Depending on what yr alpha you had the shaft to shaft is probably the same as the Bravo.