Oil pump drive shaft

[KMcCullah]

I've been trying to get my 504 together but keep running into fitment issues. My latest boggle is the oil pump drive shaft. I'm trying to use an ARP 154-7902. I've always used the Milodon 22550 in the past but never really paid attention to how deep it engages the 1/4" broach in the distributor until now. With this early Genesis block I'm not leaving any stones unturned.

So how deep should the hex be going into the distributor? I'm seeing about a 1/4 inch right now. Which doesn't seem like enough. If I slide the retainer washer down the 1/4 hex shaft I can get about 5/16 end play between the oil pump and distributor. Which seems like a lot. 

So what's going on here? What should I be seeing? 

[jayb]

That does seem like a lot of end play.  Can you measure the length of the driveshaft from end to end and post it?  Maybe its a little short...

[Barry_R]

The shaft will drop all the way into the pump when installed.  When that far down, how much engagement will you have up top in the base of the distributor?  I don't think I've ever had a problem with length - but it is probably a good thing to check.

[Drew Pojedinec]

I don't think I've ever had a problem with length

 

[thatdarncat]

I just checked four shafts I have sitting around here for comparison purposes, although I don't have an ARP one. I have a Ford Motorsports Heavy Duty shaft still in the package, but probably 20+ years old, 8 1/2" long, a Heavy Duty black hardened steel one of unknown brand, 8 1/2" long. A TRW aftermarket stock replacement 8 9/16" long and one that's probably a stock Ford shaft, 8 9/16" long. Both the stock and stock replacement have a longer, pointed "tip", which of course doesn't actually engage the walls of the distributor shaft, so although they are a tiny bit longer it doesn't do much.

[gdaddy01]

make sure it is not a 302 drive , not sure about the lenght , but it is 1/4 inch , I think