Bolt specs

[captndave737]

Does anyone know the bolt specs for the bell housing to engine block? Are the bolts supposed to have washers on them? I'm pretty sure they were grade 5 but not sure.
I know they're 3/8-16 but what length? 1-1/4"? 1-1/2"?

 

[hensleyt]

Definitely no washer. Got to be 11/2. Grad 8 will have better bolt head matting surface,good quality grade 5 will too.

 

[hensleyt]

Not got to be. But my best guess it was 11/2 in.

 

[SS/GN]

ARP is what I used.
Bell housing Bolts 129-0901

 

[SCOOBY DOO]

Specs for anything and everything you ever wanted to know about these engines.

Factory Engine Specs

 

[captndave737]

Thanks. I had a mix so I went with grade 8 1-1/2"

 

[captndave737]

Specs for anything and everything you ever wanted to know about these engines.

Factory Engine Specs

That's taken from the shop manual which I have but it doesn't list the grade or length of the bolts.

 

[pacecarta]

That's taken from the shop manual which I have but it doesn't list the grade or length of the bolts.

3/8-16 1.25" grade 5
according to illustrated manual was originally GM 9440954 phosphate finish .. but discontinued

 

[hensleyt]

Just found OEM bolt 1 3/8

 

[captndave737]

Thanks all. I had a mix of original and others. I have no idea how I lost some of the originals. I now have all grade 8- 1 1/2" installed.