i got a 1983 searay 270da, with a merc 330 (serial#6255661) tr/trs drive unit (serial#6387738) and transom plate (serial#6203277), with a velvet drive trans model#10-18-014, serial#6643.
ok bought the boat...put it in runs beautiful, had a growl when turning and trimming, i knew either gimbal...
back again..got the drive...all worked out good there..boats in the water...and it still floats!!...even after the big storm that hit us here in milwaukee today,, anyway...about exhaust manifold temps...i have a 1980 merc 260, in a 26ft century 7000, serial 5376489...went out...got the IR temp...