top altinator mounting hole not threaded

[6t727t2]

New remanufactured Delco, no threads in top hole, factory defect? Just use bolt, washer , nut? or return it?

[Wrenchbender Ret]

It is a defect. You should return it if it is not too inconveniant. I have used a bolt & nut & washers many times when the threads were stripped.
George

[Thealien]

Tap it?

[57larry]

what's the easy way? tap, bolt & nut or return it?

[HO455]

The easiest is put a nut and bolt in it.
The right way is to return it and require the supplier to provide the correct part.
Tapping it may or may not a work depending on the size of the hole that isn't tapped. If it is too large then the next size up bolt is likely going to be too big for the bracket.
We Hot Rodders are too quick to modify a new part that is incorrect in order to get things done. But the reality is that after 60 plus years manufacturers still don't know how to make a correct alternator bracket for a SBC since no one ever returns them because it doesn't fit. So they keep selling stuff that doesn't fit correctly.
As I am guilty of this too I will now get off my soapbox.

[Ol Blue K20]

Originally Posted by HO455

The easiest is put a nut and bolt in it.
The right way is to return it and require the supplier to provide the correct part.
Tapping it may or may not a work depending on the size of the hole that isn't tapped. If it is too large then the next size up bolt is likely going to be too big for the bracket.
We Hot Rodders are too quick to modify a new part that is incorrect in order to get things done. But the reality is that after 60 plus years manufacturers still don't know how to make a correct alternator bracket for a SBC since no one ever returns them because it doesn't fit. So they keep selling stuff that doesn't fit correctly.
As I am guilty of this too I will now get off my soapbox.

Where did you find a soap box?....

[6t727t2]

Will return to NAPA, I guess delco doesn't mean usa made anymore? Maybe someday again?

[MARKDTN]

It may not be a defect. There are some non-automotive applications of the 10SI alternator that use a bolt with a nut or threaded bracket because the alternator is fixed and something else is used to tension the belt. You could thread it, use a nut on the back, or helicoil it.

[ChevyRacefan]

Nut,washer, bolt. Done.
Unless you need chalkmark correct.
I much rather the nut and bolt, over the threads in the case And a steel bolt.

[Troy Sr]

You could Heli-Coil it.

[NorCalC20LWB]

I'll add my opinion that it may not be defective. The upgraded alt I put in did not have threads. Also, agree with Andy, more secure to use a bolt and a lock nut. Much easier than drilling and tapping. Doesn't look bad either.