If half groove bearings were stock, why are most clevite bearing kits full groove? Did they determine the full groove bearings were an upgrade over stock and met more folks needs when rebuilding these small blocks?
Remembering you asked for bearings for a stock build...
A couple reasons in my opinion:
1. They have a purpose - they allow full time oiling of the rod bearings. (note YR's commentaries) I disagree with him given the vast majority of engines being built by enthusiasts on a site such as this don't need them. High rpm/high load/sustained rpm engines
do need them. In fact these engines might need a higher quality, higher eccentricity bearing too. They also need machining for wider clearances, larger oil sumps, better pans and pickups, and better oil pumps. In any "lesser" application they are simply emotional relief and added expense.
2. A lot of people ask for them because of publicity and upselling.
The question I'd ask is if the 340, 340+6, or 440+6s got full grooved bearings. They got the same bearings as the other production non-performance V8s. That's with factory red lines of 6500+ on the tachometer included in those packages and a warranty. I can tell you, the 340s, 360s, and 318s I had years ago had nothing more than stock bearings and factory lower ends, and had no issues running for miles wide open, 6K rpm plus, on the highway. I didn't have the cash to rebuild, or the tools to check them out properly.
I feel one is MUCH better served getting high end machining done to correct the "factory spec" machining tolerances, oil clearances, and balancing issues and running a std volume oil pump with stock bearings than getting the less expensive machining, plastigaging the clearances, and buying things like girdles and big oil pans and big oil pumps on a street engine. Even and aggressive street/strip engine. Just my opinion of course.
