I have two sets of lug bolts and am wondering which, if any, are what would have originally come on my 73 with steelies. The black ones below have a divot in the top and have 25mm of threads.

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The silver ones have a rounded top and have 40mm of threads

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silver ones for alloys..ball seat

Post #1 on this thread has a nice picture of presumably original steel lugs with the divets you show on the head.
http://www.914world.com/bbs2/index.php?showtopic=74857

I know the lugs are shorter for the steel wheels. One source (Tech Tips) indicates the steel lugs were 1.5 inches (and the alloy lugs 2.5 inches), but I think that these are not correct -- alloy is about 1.5 inches.

Wow, that is a keen eye you have there! Thanks for linking that thread. So I guess now it’s just a matter of ensuring that the black ones are the right length. I’m also curious what the original finish would have been on these (the ones I have look to have always been black but I guess could have been blasted and repainted).

Doug,

Sorry to change the subject, but what is the story on your avatar?
Can barley see it, but would like to know more -

Thanks -

That’s my engine stand (been working on the resto for 5 years and it’s rhe only thing that’s actually finished and so worthy of an avatar pic). See this thread:

http://www.914world.com/bbs2/index.php?sho...37934&st=20

The top bolt with divot on head is the correct wheel bolt with 25mm threads.
The domed head, as stated, is for the alloy wheels. Be careful with them, the silver coating is probably cadmium (nasty stuff but corrosion resistant) and underneath that is a copper plating. If you see a pea green color that is the copper corrosion like you see on copper roofs, and this is also pretty good protection. So clean carefully and perhaps use a little silver paint on the heads.
I'd be interested in the long bolts.

Interesting! IIRC, some (2-4) of the silver ones are shorter. I have them stored with my other stuff on the farm 2.5 hours away. Next time I'm there I'll take pics of all of them for you (that probably won't be for a month or so).

Doug, just edited my previous post. The bug bolts are only 3/4" threaded length. The correct ones are 1". There should only be one length for the alloy bolts. How many do you have? Post photo of different lengths.
PS, I had a great chat with Gord Luy when he flew down for the 50th reunion at Mosport. Maybe I'll get a chance to visit Winnipeg again next year. I get there occasionally when visiting relatives.
Dave

Thanks for the update Dave. I'll had measured them last year and was posting from memory so I'll re-measure when I'm there and ensure that there are 25mm of threads on the black ones. I'll also get the info on the silver ones at that time. Yes, Gord is a guru and always willing to share his wealth of information. Do let us know when you are coming to Winnipeg and we can have a 914'ers get together.

My first impression on the first photo was that the bolts are bug bolts I think was true now. The head length and the thread length appears to be equal, and that would indicate a threaded length of .75", and thus too short for the rear wheels. They are okay for use on the front with steel wheels, but not on the back where the brake rotor adds the extra quarter inch.