there is a crack in my block it looks like something fell on it at some point or smashed into it, its on the transmission housing on the bottom bolt where the oil filter goes. do you think i can get it drilled out and re-threaded instead of changing the whole block. the crack is just a hairline crack its not all the way through the block.

 

Drill and retap. I'd use some red threadlock just for comfort sake.

 

that's nothing to scrap the block over, just drill it out, tap it, and throw a little paint over the shiney spot. I had an engine that actually had that hole stripped out really bad and I didnt realize it until I was bolting the tranny up. I just put all the other bolts in and left that one out, ran it like that for about 5 years with no problems and then retapped it after I pulled the tranny for a trans swap. Don't lose sleep over it.

 

I agree with them

 

Looks like it got "squished"... Weird. I might get the machine shop to drill that out, just to make sure it's aligned right. Cast iron is pretty soft, so you might have the bit wander. A hand drill is dicey IMHO.

If you have a hairline crack going outwards, when you tighten the bolt, there's a good change it'll spread the crack, or at least get the block to flex. I had that happen on my outermost starter bolt hole.

I used a high nickel rod, and welded it up a bit. I might recommend you just borrow a torch and braze it. That'll help.

 

you should really have someone that knows how to weld cast take care of this.
if you do it your self
drill stop the crack
preheat the area up to about 500 degrees slowly
weld/braze
post heat down to about 250 degrees slowly
then redrill and retap
good luck
mike