Is your mounted to the block...or the raw water pump ? And...if it was me who told you to get a merc pump...thats because thats what is supposed to be on it.

As far as the push rod and pump lever and fit there is no difference between automotive and Merc pumps. Holley makes some fine marine mechanical pumps as well as Carter,Mallory and Mr. Gasket. Sounds like you didn't have the lever on the push rod correctly when you installed it. As stated earlier turn the engine over so the rod is at it's farthest point in. Makes it a lot easier to install. If the rod is in at it's lower point and stuck turning the engine over should push it out. Roll it on a flat surface and see if it's bent.

FYI did get a brand new marine fuel pump for this job. I know a few of you asked about that.

Marine or standard auto fuel pump will work. I have an extra one if you need one. THERE IS a bolt on the fromt of the block to keep the rod in place. If you overtighten this bolt it will bend the shaft or put a little grove in it and won't come out. YOu might able to use a small screw driver and just keep nudging it down through that bolt hole. YOu can also turn the motor for a sec and it will "push" the rod out enough you can grab it with pliers.
When you install. use some HEAVY WEIGHT greese on the rod. The greese will not let the rod slip out while you get the pump back on. Just put a bunch in the hole and on the rod and just push it up. IT will stay "up" long enough to get the pump back. THe pump will go back in place even if the rod is out. It will just press on the fuel arm, but you won't get any gas.

Good luck.
P

I removed the NPT plug just under the mounting flange, stuck my pinkie in there to hold the rod up, then with my other hand, got the lever of the pump between the rod and my pinkie. I was able to thread a few threads of each bolt in place to hold that position and then tightened them down, making sure that nothing was bound up when tightening.

If the rod was scored, the block may be also. You may need to get a small hone to clean up the block before you go any further. Try bumping the engine over and the cam will push the rod out.

Replaced the push rod with a new one. Greased it up and it stuck in place with no problem.

Reinstalled the pump and everything is working as it should.

Thanks for all the help.