70 Big Block Water Pump Bolts

[Allen N.]

What is the length and typical head markings for the three bolts in a 70 big block water pump? What is the finish of the stud and nut?

Thanks,
Allen

[Allen N.]

Re: 70 Big Block Water Pump Bolts

I have searched the Judging Manual and the archives for hours. Can someone just tell me a typical head marking for a bolt holding a 70 big block water pump?

[Jim M.]

Re: 70 Big Block Water Pump Bolts

Hi Allen:
The water pump bolts on my 1971 LS-5 have 3 hash marks and "TR" on the bolt head.

Best, Jim

[Joe L.]

Re: 70 Big Block Water Pump Bolts

I have searched the Judging Manual and the archives for hours. Can someone just tell me a typical head marking for a bolt holding a 70 big block water pump?

Allen------


My recommendation: you can obtain a kit containing all 4 of the fasteners you need (3 bolts, 1 stud) with period-correct headmarking from most of the Corvette vendors. This comes at a quite modest price. That's the way to go if period-correct headmarking is what you seek.

[Rick N.]

Re: 70 Big Block Water Pump Bolts

My 1970 has head marking TR inside the 3 hash marks for 5 grade bolt.
The 3 bolts and 1 stud measure 1 11/16" long.

The bolts and stud are original NOT reproduction.

[Allen N.]

Re: 70 Big Block Water Pump Bolts

Thank you very much for the responses.

Joe, I always check Corvette vendors, but sometimes their head markings are not what the Judging Manual or archives indicate are correct for my car, so I like to confirm before buying. This is especially the case with the water pump bolts which get painted with the engine. I would hate to get the engine painted and find out the head markings are not correct.

[Joe L.]

Re: 70 Big Block Water Pump Bolts

Thank you very much for the responses.

Joe, I always check Corvette vendors, but sometimes their head markings are not what the Judging Manual or archives indicate are correct for my car, so I like to confirm before buying. This is especially the case with the water pump bolts which get painted with the engine. I would hate to get the engine painted and find out the head markings are not correct.

Allen------

If the judging guide says that a certain manufacturer's headmarking is singularly correct for these bolts, then the judging manual is wrong. Just about any period correct manufacturer's headmarking should be considered correct. I believe that the reproduction bolts have a "TR" headmarking but I'm very confident that others were originally used, too.

[Ron G.]

Re: 70 Big Block Water Pump Bolts

Allen,

What Joe said is correct. I have mentioned this before on the DB in regards to other scenarios. GM used a variety of hardware suppliers that I like to refer to as the GM family of hardware. What was most paramount is the grade. Typically most engine hardware was plated black oxide which includes the stud. The engine orange was then painted over it. One other point only for the true "purist" is that most reproduction hardware bolt logos are usually not as prominent as the originals. That does not mean that there will be a point deduction, it is just something for your own FYI.

[Allen N.]

Re: 70 Big Block Water Pump Bolts

Thanks to everyone for your help.