Please Help With Bolt Size

[SpecialBlend]

I have a 79 620 KC, I am in the process of getting the truck ready for smog and need to know what size bolts to use to attach the following pieces to my engine block

 

 

I believe the air pump mounts to that blue bracket once to bracket is attached to the engine block here

 

 

I also have the idler arm for the air pump but no idea what or where it mounts to.

 

 

If any one can help me out or give me any advice I would really appreciate it. I can provide more pictures if needed, thank you all for your time.

[DAT510]

I think the bolt heads were 14mm.. I still have that bracket along with the bolts.. I'll check tomorrow for ya

[EricJB]

M10x1.50 or M8x1.25 Most of the 12mm or 13mm bolt heads are M8. 14mm and 15mm is usually M10. 10mm bolt heads are M6x1.0

[AtlanticCoastDatsun]

threads like this make me glad I dont live where the state makes me smog my truck :cool:

[datsunaholic]

You appear to have 2 incompatible brackets there. The triangular one goes on the bottom 3 holes, then the air pump bracket that you DON'T have goes above it. I don't know what that upper bracket you have is off of; it's a combined unit and I suspect it's for a car with both a smog pump AND Air conditioning. A truck won't have the A/C on that side (won't clear the steering gearbox) so all that is there is the pump and idler.

[SpecialBlend]

Dat510, If you could check the bolt and possibly take a picture of what your bracket looks like for me I would really appreciate it. Sounds like it would clear a few things up for me.

 

EricJB, Thank you for that information. In the future that should come in handy though

 

Datsunholic, Thank you for helping me out. Did they use the same bracket system through all years? I mean is the air pump mounting system any different from say 1975 l20b to 1979 l20b? Could you by chance take a picture of the bracket I am missing so I know what to look for? I really appreciate all your time and help. Your information alone has kept me from possibly mounting the wrong hardware to engine. If you can help any more I would really appreciate it. Thank you again

[datsunaholic]

I'm not sure if they're the same. I am stripping off the air pump on my '76 at some point (the pump is seized and the idler is also bad). Somewhere I have a bucket full of those brackets, but Lord knows where it is. That smog stuff is how I ended up with my '78 4X4... Utah required the equipment, Wyoming didn't but the owner was in Utah. He bought a pile of brackets, pulleys, the pump, hoses, etc but couldn't figure out where it all went.

[DAT510]

im almost certain that it goes like this... I reread your post, and i don't remember that blue bracket, this came out of a 76 620

 

 

 

Here is the remaining things i could find

 

 

[SpecialBlend]

Dat510, Thank you for getting back to me and for the pictures. I really appreciate that. Couple questions though.

 

With that bracket you are holding up the engine block, If you mount it in that location where does the idle pulley mount to?

 

Do I need an idler pulley?

 

Once again I appreciate all the help any information helps.

Thank you

[DAT510]

Dat510, Thank you for getting back to me and for the pictures. I really appreciate that. Couple questions though.

 

With that bracket you are holding up the engine block, If you mount it in that location where does the idle pulley mount to?

 

Do I need an idler pulley?

 

Once again I appreciate all the help any information helps.

Thank you

 

Sorry for not getting back to you :(

i had a internet outage for a while.

i'm actually not sure, i'll investigate some more :lol:

[DAT510]

 

 

i think that's the idler pully right there behind the hose to the right of the crank

[Tucson620]

Special Blend - Check your PMs. I'm really curious about that combination AC/smog bracket.