Beside the lugs, what SAE fasteners do our trucks use? I would assume most fasteners would be metric but given that we have a Buick engine I am not sure.

 

The lugs are metric, 27mm hex head with an m14x1.5 thread

The driveshaft hardware is sae.

The fill plugs in the diffs aren't metric or sae they are bsp.

 

the majority of my manifold bolts as well as some of the ones holding the water pump are now 3/8. overlooking torque specs was a great help in this conversion.
not sure that I have encountered any sae in the engine....

 

Bell housing to engine block.

 

what are the head bolts? 16mm or 5/8

 

Dusty1
The head bolt is a 7/16th UNC hence the head is 5/8 socket size.
The LR engine has progressively gone metric as it was developed from its Buick roots.
So goes the basic block and head which has stayed UNC, but LR added on's are metric.

As an example the main bearing cap bolts are UNC, but the side girdle bolts introduced on 4.00/4.6 derivatives are 8x1,25 metric.
Equally the heads are largely UNC but valve cover hold down screws are metric.
The easy to catch you out is the timing cover!
Major through bolts into the block are 5/16th UNC, pan/bolts studs are 8x1.25 metric and the water pump is 8mmx125 with a mini hex head calling for a 10mm socket.
No confundo! Cheers
T/V

 

Do you know the sizes of the driveshaft hardware?

 

I believe it's 3/8-24, grade 5. 9/16 hex on them.

 

Oh, also if you have rotoflex, the stuff at that end is metric.

 

You've got to laugh at these half and half vehicles -------------- haven't you?