350 MAG MPI Head Bolt spec

AusFox

Cadet
Joined
Sep 28, 2025
Messages
19
Hi all,
Has anyone got the 350 MAG MPI head bolt sequence and tensions?
 

Cdn20valve

Seaman
Joined
Aug 10, 2015
Messages
52
Someone double check these figures, but i believe they apply to the mag also.

65 lb-ft in three increments (e.g., 20, 40, and 65 lb-ft)
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
52,263
its also on the package the head gasket came in as well as the package the head bolts came in.

if the old bolts are TTY (Torque to Yield), then they are a one-time use bolt.

if the head of the bolt is 1/2", its a TTY bolt. and you need new head bolts. if the head of the bolt is 5/8", use the increment above.
 
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