'66 L79: What are common head marks for fan clutch to water pump bolts

[Gary B.]

The '66 TIM&JG spells out the grade 8 cad/zinc feature of the fan clutch to water pump bolts for '66, but it makes no mention of typical head marks. Does anyone know what head marks have been observed on Bowtie 66s?

Thanks,

Gary

[Henry J.]

Re: '66 L79: What are common head marks for fan clutch to water pump bolts

Gary:

I can tell you this: at this location on my 66 L79, I have one bolt with an L8 headmark and 3 bolts with an S headmark. All these bolts are Grade 8.

[Kenneth F.]

Re: '66 L79: What are common head marks for fan clutch to water pump bolts

Gary, My L-79 had a warranty pump installed in 1967. I cannot be certain the original bolts were re-used. The 2 on the driver side have an M with 3 lines radiating from the letter. Top bolt on the passenger side is a TR with 3 lines radiating from the letter. Bottom bolt looks like an O with 3 lines radiating from the letter.

Ken

[Kenneth F.]

Re: '66 L79: What are common head marks for fan clutch to water pump bolts

Gary, The fan clutch bolts are all grade 8. There is a small marking at the center of the bolt head. I can remove a bolt to better read the marking if you need more information.

The VIN is 11,xxx

Ken

[Gene M.]

Re: '66 L79: What are common head marks for fan clutch to water pump bolts

If I'm recalling correctly I think it is "AS" head mark and grade 8 fine thread.

[Michael M.]

Re: '66 L79: What are common head marks for fan clutch to water pump bolts

My 1966 L-79 has SBC with six radial lines as a head marking grade 8 fine thread.

[Jeremy R.]

Re: '66 L79: What are common head marks for fan clutch to water pump bolts

My 66 L-79 bolts have the headmark AS and the grade 8 lines

[Gary B.]

Re: '66 L79: What are common head marks for fan clutch to water pump bolts

Thanks all. It looks like there are several options of head marks.

Gary