Originally Posted by 99Moneypit

If you haven't tried to use a thread chaser tap yet, I'd still try it before drilling anything. Sometimes there's still enough 'there' that the chaser will straighten things up. Before you drill, make sure the bolt you plan on using still fits through the hole in the balancer! I know helicoil gets a bad reputation but most of the time the failures are caused by a bad installation. I'm not saying it would be my first choice for retapping a crankshaft but we're pretty much stacking bandages on top of bandages with this particular truck out of need, not want and I know machine shops that have helicoiled crankshafts without any issues. If you're worried about it working it's way out, throw some loctite 2620 (high heat applications up to 650F) of 262 (up to 350F) if you can't get the 2620 for the helicoil to crank joint, NOT the bolt to helicoil joint or you'll never get it back out without a torch.
As for the transmission cooler line, I'm at a loss as to the exact size but if you can figure out what size wrench 'used to work' before it was rounded off (use flare nut/line wrenches with plenty of penetrating oil in the future to help prevent it happening again), The supply store should be able to figure it out. Either way, try to capture as much of the transmission fluid for re-use if it isn't burned up, your clutch material is likely floating around in it and without it, you're looking at rebuilding the transmission on top of everything else too! Are you feeling that warm glow of owning a Chevy Blazer yet? 😁 Spray the current fittings down with penetrating oil and grab your best pair of vice grips if both the male and female fittings are rounded off and prepare a 2 page list of profanities to practice before removing them. If only one is rounded off, grab the flare nut wrenches (they look like a 6pt box end with a slot cut out of then to fit over the hard line and then engage most of the surface area of the fitting) AND your vice grips for the rounded fitting. You'll have to hold one and turn the other or you'll twist and Kink the hard line, ruining it. If it's already ruined, put the catch pan under the break and focus on removing the fitting with a standard box end wrench, preferably 6pt and not 12pt since 12pt engages just the 'points' of the fitting and tends to slip and round off the fitting where the 6pt engages the flats and the points of the fitting and is far less likely to round off if you use the correct size. If you can't get a flare nut wrench, you can cut a 6pt box end but they will flex more than one originally designed to be one. Cut on a flat and not a point and on the trailing edge. Hmm, how to explain trailing edge, right? If the wrench is on the fitting and hanging straight down towards the ground, the handle is at 6 o'clock. Turning counter clockwise (lefty loosey) the trailing edge would be to the right side. For tightening, to the left.

Originally Posted by 99Moneypit

I know the feeling. Our 99 Blazer was bought specifically to haul our super-shedder German Shepherd/Malamute/wolf (low content) hybrid to and from places. That was all it was supposed to do. I started driving it little by little to keep a charge in the battery and the fluids circulating. Then as a 'winter car' for work (the drivers around here don't know how to drive in the snow). Next thing I know, I've replaced the heater core (necessary evil), then the transmission solenoids (another necessary evil). Then brake caliper rebuild (and might as well do all the lines if I'm opening the system, right?). Next thing I know, I've replaced the stereo, speakers, checking the junkyard for factory heated seats (haven't found a good set yet), replacing the cargo screen at the back... They DO grow on you.