(15.1) (16) (17) (18) TM 9-2815-202-34 For model 7083-7391 only, if necessary, install eight exhaust port seals (47.1) in cylinder head. Using hammer and exhaust seal installer (103.1), carefully tap seal in place. NOTE l l Models 7083-7396 and 7083-7391 contain four bolts (33), four flat washers (34), two cover plates (35), and two gaskets (36) per head and no cover plate on rear inboard  corner. Model 7083-7399 contains six bolts (33), six flat washers (34), three cover plates (35), and three gaskets (36) per head. Install gaskets (36), cover plates (35), flat washers (34), and bolts (33) to remaining cylinder head. Torque bolts to 7-9 Ib-ft (10-12 N-m). corners of If necessary for models 7083-7396 and 7083-7399, install support bracket (37), two Iockwashers (39), and two bolts (3$) to right cylinder head. Torque bolts to 30-35 Ib-ft (41-47 N-m). Install sixteen exhaust valves as follows: (a) (b) (c) (d) (e) (f) Position cylinder head on its side. Lubricate valve stems with sulphurized oil (E. P. type) and slide valves (32) all the way into guides (72). With Install  lower  spring NOTE used valves, install in their original location. seat (31 ), valve spring (28), and upper spring seat (30) over valve stem. CAUTION Avoid scoring valve stem with valve seat when compressing spring. Using valve spring compressor (27), compress valve spring (28) and install two piece tapered valve locks (29). Release pressure on valve spring compressor (27) and remove tool. Repeat steps (a) thru (d) for remaining valves. Support cylinder head on wood blocks at both ends (right side up). Give end of valve stems a sharp tap with soft headed hammer to seat valve locks (29). Change  1 5-59