So Im just about done with my L24 rebuild, I was mounting the dizzy and as soon as I go to hand tighten the bolts they didn't want to go in after a couple turns.  The threads are messed up on the cover, my heart just dropped with all the time spent on my first rebuild.  Im wondering do I have to get another front cover and reinstall everything, Or can I can I re tap the holes on the front cover without removing it?  I can tape off the whole to the dizzy so no metal pieces fall in.  I hope this way will be ok... 

Helpful tip: you can spray shaving foam to catch metal too.

 

Also double check you have the correct bolts.  Often non-metric bolts have found their way to our cars over the years.

Neither hole enters the cover.  One is blind and one is through to outside.  And there's not much in the distributor shaft hole to worry about, since you'll just be running a tap.  They can't be that buggered up that they need re-drilling, tapping and inserting.  A greased tap should catch all of any fine aluminum shavings.

 

But I would first do what Blue says, on the bolts.  You might have a fine thread in a coarse hole or vice-versa.  

 

If you're super-worried though you could turn the engine upside down so the chips fall away from the engine.

Had a similar issues on my L20B. Since neither hole is through the timing cover, I just drilled/tapped and used a HeliCoil. Never had an issue again. 

I know the bolts fit, I tried them on another cover. But this makes me feel alot better. Im going to tap it then, thanks everyone!