In 2015 my car dynoed 70hp low. Turns out I'd lost a rod bearing the last race of the year prior. I forgot how weird the car had felt the last lap or 2 and how I'd just cruised there because we were really spread out by that point. I grabbed a crank off of CL and had it polished, pistons and rods used off of Fleabay, new bearings and gaskets, honed in my garage, all in for about $800. That motor is still in and healthy, has been good and made good numbers. It's getting replaced by an LS. While the rest of the crap is an asspain to hunt down cheap, the motor itself was $220 from the pull and pay for an aluminum LM4. Gotta find another for a spare. 170k and I'm not doing anything to the bottom end. Got a late LS1 cam for free fiddy to pop in there and that's it. I don't believe in machine shop engines for these cars when stock seems to last just fine.