What type of oil do you all use?  455 Olds here not sure what weight is supposed to be in it.  As far as I know its mostly stock but bored out .30 over.  The guy I bought it from says he ran straight 30 but I thought that was too light.  I ran it pretty good all weekend but it def needs an oil change.  About how often every 20 hrs or so?  And whats a good RPM limit?  Not that I can tell cuz the tach was bouncing all over the fucking place.

I'm using Valvoline Racing 40W in the BBC

Just once a season?  I thought it broke down and you lose protection after a couple of months.  Full syn gives the best protection is the concensus I'd imagine.  Straight 50W it is.  Anyone on the RPM?

Stock Olds RPM limit, I've read over and over the recomended limit for continual/constant driving to limit them around 4,000 RPM's with occasional short "blasts" OK to 5,000 RPM. Too much more than 4,000 RPM's and you'll starve the bottom end for oil and you will lose bearings or even a crankshaft.