When your priming your BBC with a drill motor and straight shaft (1/2" rod with a flat ground on it) will you get a large amount of oil pumping from the distributor hole coming from the back of the block where it would be pumping on the distributor shaft if it was in the engine?....On my other brand engines I use an old distributor so I don't or haven't seen this....I assume it is to provide oil to the distributor gear but appears to be a lot of oil....just wondering if this was normal, Thanks, Fred.

The oil you are seeing is oil that would be going to the lifters / rockers/ valve springs / front timing chain & gear. The distriburer has a groove in it to let the oil continue on.

That oil is supposed to go to the main oil galleys in the lifter valley. Without a distributor or a priming tool (a junk distributor with the gear ground off or removed) you're not priming the engine.
Just go to the local boneyard and buy a chevy distributor and remove the gear.
By the way Fred, did you use plenty of lube on the cam and lifters?

I thought the housing had to have something to do with the sealing the system to get oil to go to other areas...I used all the lube that came with the cam and I set the lifters in oil for sevaral days....when I started motor I got a lot of lifter clatter...how long does it take for the lifters to pump up?....I ran it about 5 min. and still clattering.....should I pull dist. and reprime it correctly before continuing? ( I think yes) Thanks guy's, Fred.

I may be off base here but if you still have clatter after 5 minutes it is not a priming issue. Anyone else? Did you have oil pressure during that 5 minute span? Check adjustment.

Did you have your lifter adjusted properly if there still clattering the are either loose are no oil.
later

I had all kinds of oil pressure....just thinking that I may have to put more pre-load on lifters also....did the half turn load as cam manufacture recommends although merc book says 1 turn...I am re-checking that issue next....Fred

You need to adjust the valves with the motor running. Back off adjusting nut until you hear clatter. Then tight down until clatter goes away. Then add 1/2 turn (Some say more but I have never had a problem with just 1/2 turn).

One other thought, are you using correct distributer? Or better question is while motor was running were you getting oil to the rockers & springs. If you were not getting any oil up there you have some serious problems.

Fred, I'll make a road trip over to your place this weekend if you'd like. I'm sure we can sort out the problem.
I've always set the lifters without the engine running and never have had a problem. I know people that set them running but that can be difficult to do with your manifolds.
Call me if you'd like.