I seem to be having an issue finding one online anyway.

No luck so far. Today I'll be hitting up some local stores to see what I can find.

 

Good luck!

I know M16 x 1.50 is common but is 18tpi.

M16 x 1.25 is not so common I think but, hopefully you'll be able to find something.

Carry one of the fittings with you so if you can't find a plug you may get lucky and find a cap to fit the big end. I'm thinking a cap may be easier to find.

Anyway, just trying to help. Let us know what you come up with.

 

Looks like we are just going to see if we can weld the fitting shut and bolt them back in. Should cost a cheeseburger and fries. We are just finding nothing local. Even Fastenal can't special order that size.

Plus if I have to put the SAI back in, i'll just drill them back out.

 

Yeah weld it up. They're stainless I think.
Round here they want $50 just to switch the welder on. I do most of my welding myself but I did have to get a 6" to 8" crack in an inch thick cast iron wood heater welded up with nickel rod and they hit me up for bout $150 and that was with me taking the heater apart myself and just carrying the part that needed welding.
oh well....lots of overhead in a shop like that and I can't complain, they did a much better job than I could have done. plus I wanted it welded on both sides and was kind of particular about how I wanted it done which probably cost me extra.

 

I was thinking something like this and a common 1/8 plug
Auto Meter

 

That's what i was thinking dusty or even a short bolt but, he needs 5/8 x 20tpi or 16 x 1.25 instead of 5/8 x 18tpi or 16 x 1.5
You got any idea who may carry em in that size 20tpi? If he finds them I may grab some myself for future projects.

 

I will find some
I need some too

 

not ideal, but works....with some help
Through Bolt Gal M16x125 20qty | Better Hardware - Trade Quality Supplies At Lower Prices


stainless and galvy....all I could find in these.


thinking out loud: what is the muzzle on m14s/m1a? I think its 5/8 x 20 or maybe 24....can't remember and i'm in Houston, otherwise I would look. If same I may have something that works or at least a tap and die

 

just use the SAI holes to inject nitrous

 

Thanks dusty. anchor bolts. good find. I'll have to check around locally to see if any in that size. Would be easy enough to cut to length and grind a square head or a slot to run it in.
Maybe the op will see this before he welds his up.