Mirror mount holes

[Hawssie]

I know this is a minor thing but its kinda bothering me. I talking about the 3 holes in the door for mounting side mirrors. I have 4 trucks/blazers for reference. I have read 1970 was when they started using the small square sport mirrors without the long stem. And they seem to mount right about in the middle of the division bar between the vent and door window. But out of my 4 vehicles my 69 has the 3 triangle bolt holes for the long stem mirrors which are located farther forward toward the fender, as it should but so does my 1970 C10 and one of my 1972 blazers. My other 72 blazer has the small stem mirror in the right spot. I am wondering about the other 1972 blazer and mostly about my 1970 C10 as thats the one I need mirrors for. I guess I will have to weld in the 3 holes if I want to use what I thought were the right mirrors for it. I was just wondering why it didn't have the holes for these mirrors there in the first place instead of the ones for the 1969 down or am I missing something. I know I can mount any mirror I want to but to be correct was the long stem mirror still installed on 1970 models? I should mention the 1970 had camper style mirrors on it when I got it. The other Blazer I cant remember what it had(it has nothing mounted now, was stripped long ago for paint but it is a CST)

[SS Tim]

The small square head mirrors were 71-72. The 70 mirrors were arm with a square head and 69 were arm with a round head. Take a look here this should clear it up some for you. Pretty sure the assembly manual has the mounting locations for the small 71-72 standard mirrors if that is your choice and IIRC they have different locations left vs right.
http://67-72chevytrucks.com/vboard/s...5&postcount=11
http://67-72chevytrucks.com/vboard/s...d.php?t=565861

[SS Tim]

Here is an assembly manual clip and a thread link for you to work off of. Unless you really must have the small and close mirrors I would suggest something bigger like a DG4. After all if you can't see behind you what is the point?

http://67-72chevytrucks.com/vboard/s...d.php?t=417037

[Hawssie]

Thanks that helps

[Hawssie]

Those triangle set of holes is what I have on all but one of my vehicles. So they had them in 1970 too. That explains everything except my one 72 blazer that has them too. I think I will go with the long stem square head on my 1970 now I know they are for the right year. Also since then I wont have to drill new holes or more importantly have to weld up the old holes. Thanks.

[54belair]

Some have expressed questions about the location center lines shown on the assembly drawings ( such as a vert. line 15, and a horiontal line 35), I finally figured out part of it----these are locations measured from the bottomof the truck (somewhere), and the vert. line 15--is relative to the front of the cowl of the truck---measured in inches.

So, the triangular mirrors are positioned at aprox. 15 in. back from the cowl and 35in. up (from somewhere).

On aprox. page 45-ish in the assembly manual it shows these----but doesnt say anything about the passenger side being different. Im going to use factory measurements for drivers side---then sit in the truck and have someone position the passenger mirror.

[SS Tim]

Did a write up on the locations about three weeks ago that you might find to be helpful information. However I still have not located the verticle or horizontal datum reference points "0 point" but it is not a fixed edge. Best bet is to use a referenced factory hole and measure from there.
http://67-72chevytrucks.com/vboard/s...d.php?t=579296 post #9

[snipescastle2]

I had one door that already had the holes in it, I took a piece of paper and taped it to the door and traced the pattern onto it, then reversed that, laid that on the opposite door and marked the holes. HTH
Ben