Quote Originally Posted by jim_in_dorris View Post
I fought that problem for years in my truck. It turned out to be both heads were cracked at the exhaust seats. And after it warmed up it would miss/ stumble at idle and light throttle. 193 tmi heads are prone to crack at the exhaust seats. My 2 cents
Are you referring to my problem, it's not clear given the quote above your post.

I haven't been able to install the new grounds yet (owing to work and weather), but I have fabricated a few of them. One thing I did notice is when I relocated the sensor grounds from the thermostat bolt to the manifold bolt nearby, apparently I didn't run a ground from there off to the battery/body. So that is a HIGHLY suspect potential cause of this issue. Some would say relocating the grounds form the thermostat bolt is the issue you'll just never convince me a bolt threaded into an aluminum manifold is any better a ground than using a bolt going into the iron head (which, if we are being picky, the manifold was bolted into, so it should actually be a BETTER ground as it cuts down on the chain of grounds to get back to the negative terminal on the battery. ... well, you know, if I'd actually run that darn wire ;) )

This is clearly going to be the FIRST ground I improve. I built a 2-GA cable out of welding cable with a copper lug hammer-crimped to it and soldered (honestly, solder would be just fine on its own, and I've built many a cable that way) with marine-grade heatshrink over 3M electrical tape to seal against the weather.