I'm working on my 63 impala (283 motor) and the previous owner had put a beat up Delco HEI distributor on the car, but it's so large that you can't really time it correctly-- the cap hits the firewall and you can't rotate it. So I got an original style distributor to replace it with.
The problem is that the spline on the bottom of the new (old style) distributor doesn't line up the same as the spline on the HEI. The HEI spline is exactly aligned with the rotor-- if the rotor is at 12 o clock, the spline is too.
On the new one, the spline is at maybe 2 o clock when the rotor is at 12. So when I drop the new one in, I can't get the rotor to align to the proper mark I made showing where the rotor from the old cap was pointing.
I hope this is clear!
I'm not sure how to proceed. It seems like the safest thing to do is to move the engine to TDC and then drop the distributor in and make sure the rotor is pointing at the contact for cylinder 1.
However, I kinda think it'd also be ok to use the position that the motor is in right now, and just try to turn the oil pump with a screwdriver down the distributor shaft hole until it lets the distributor drop where it's supposed to be.
Any tips on how to deal with this?