Anyone know a good way to remove the SB oil pump drive shaft with the oil pan and intake installed?

I have my 383 buttoned up and bolted on my frame. When I went to install the distributor I couldn't get it to engage all the way with the cam gear.. I soon realized it was engaging with the oil pump shaft BEFORE getting to the cam gear. I made a couple measurements and discovered that the distributor drive shaft is sticking up about 3/4" too far. The distributor is syncing with the the oil pump driveshaft, and bottoming out against it well before the distributor is really engaging the cam gear.

I tapped the shaft with a hammer/screwdriver a couple times to be sure it was fully engaged with the oil pump. At this point I am thinking maybe the machine shop installed a big block shaft (are those about 3/4" longer)?

Am I losing my mind or does this make sense?

Anyone know a good way to remove the SB oil pump drive shaft with the oil pan and intake installed?

I have my 383 buttoned up and bolted on my frame. When I went to install the distributor I couldn't get it to engage all the way with the cam gear.. I soon realized it was engaging with the oil pump shaft BEFORE getting to the cam gear. I made a couple measurements and discovered that the distributor drive shaft is sticking up about 3/4" too far. The distributor is syncing with the the oil pump driveshaft, and bottoming out against it well before the distributor is really engaging the cam gear.

I tapped the shaft with a hammer/screwdriver a couple times to be sure it was fully engaged with the oil pump. At this point I am thinking maybe the machine shop installed a big block shaft (are those about 3/4" longer)?

Am I losing my mind or does this make sense?
=
If the shaft is turning the pump it sounds like you are correct it is a probably BB shaft.
You cannot remove it from the top
Pan has to come off :(