Bobby, your '76 dash will probably look like my '74 did when I got it...I took all stock Wellcraft dash components gauges and everything out and redid it w/ Starboard...at the time, I couldn't locate any 1/4" , so used 1/2'' seen here...pictured here is sonar/gps combo ... hope this gives ya some ideas ;) ...
and my antenna went FLAT on the bow-deck...reads all the sats and outta the way ;) ...