1969 small block coolant drain plugs
 

I am in need of two assembly line original cylinder block coolant drain plugs for 1969 small block engines. If anyone can help with this I would appreciate it. I assume they would have a head marking of similar nature to other engine compartment bolt heads of the era unless I am mistaken. Thanks.
Bob

Re: 1969 small block coolant drain plugs
 

all the original ones I have don't have any markings I don't think they ever had any markings stamped into them

Re: 1969 small block coolant drain plugs
 

I would say 80 to 90% did not have head markings. I do have some Originals that have L and others that have s on the heads. Also I have NOS ones that have a raise dot That's off center

Re: 1969 small block coolant drain plugs
 

https://www.yenko.net/ubbthreads/pics...0_16.31.10.jpg
From left to right. 2 raised dots off center, 2 depressed Center, 2 small s head marking, 2 large s head marking and one later model 5/8's hex instead of the correct early 9/16 hex. Still looking for my set with L head marking.

Re: 1969 small block coolant drain plugs
 

One more thing to add the drains are the same for small and big block

Re: 1969 small block coolant drain plugs
 

I have a set that has an concave head, but I believe that it is an aftermarket plug of some sort. It has a clear zinc plating as well. Do the judges look at these things? I have not heard any discussions on this topic. Is it not something to consider? I am in the process of painting the engine and thought I should try to verify this before I continue. Maybe I should just blast the zinc off of the ones I have for good paint adhesion and not worry about it. I appreciate everybody's help on this.