Buick 350 and 455 V8 Head Bolt Torque Sequence - 1970

[schwemf]

The head bolt torque sequence show elsewhere on this site conflicts with the 1970-1971 Buick Service Manuals as well as Service Technical Bulletin that I've attached, dated February 1970.

The wording in the attached Service Bulletin clarifies that (1) the picture shows a 350 V8 head but (2) the torque sequence is the same for both 350 and 455 motors. The wording in the Service Manuals isn't as clearly stated.

-mike

 

[LARRY70GS]

Torque sequences are more or less the same. You are aiming to draw the head down evenly. It starts in the middle and works it's way out. Go through the sequence 3 times. Start with 30% torque, then 60%, and then 100%. You'll never go wrong that way.

 

[Bob]

I have updated the pages to show both torque patterns, the early and the late. The pages displayed the 350 torque pattern for engines until 1969. In 1970 they changed to the pattern you present.

Thanks for drawing that to my attention.

Buick 350 Engine Specifications

Engine Torque Specifications for most Buick Engines

 

[LARRY70GS]

Bob,
I was looking at the online 69 Chassis manual the other day. I was looking under the Group 68 Engine electrical section. When I clicked on "A" for Generator, I got Engine Tune Up. Just thought I would bring that to your attention. Thanks.

Generating System, 1969 Buick Chassis Manual

 

[Bob]

Larry,
Thanks, got it!

 

[LARRY70GS]

Excellent.