351w oil pump

Hello everyone, can anyone tell me if rotation matters when replacing an oil pump on a 351w?

Thanks Keno, I understand now. I was restoring a '78 ski nautique and had the RR engine rebuilt when I found a beautiful '91 sport for 8k. The engine in the sport ran great for a couple hours, but then it stalled and hydro locked. I pulled the heads and one was cracked. Since I had not installed the rebuilt RR engine in the 78, I'm using it in the sport. I'm replacing the cam because the sport is LR with a new upgraded 1:23;1 transmission. That's why I was concerned about the pump. I'll rebuild the leftover engine when I can afford it. Can you think of anything else I should do while I have both engines on stands?

Hellerides wrote: Can you think of anything else I should do while I have both engines on stands?

The transmission is the 80A and it looks brand new. They used a piece of rubber on top to protect the muffler which seems to work. I haven't pulled the engine block out of the sport yet. I will be pulling the trans out of the way to install a new shaft that came with the boat. Should I use the new plastic cutlass bearings from nautique parts online? The original 78 block had a pin hole in one of the cylinders so my mechanic used another block and I have not pulled the oil pan yet. I do most of the work at night because of the heat in Orlando and I just turned 68. I'm also taking pictures as I go and soon as I pull the oil pan and the engine out of the sport I'll figure out how to add a couple pictures. I really do appreciate your time and expert advice. The sport came with a 2015 boatmate trailer with vault bearings and it sits a little higher. I have a 2 ton cherry picker that has some reach, but it's going to take a minute to get that engine out safely. I will let you know my progress tomorrow.

That was my first thought, but when I dropped the heads off from the sport my mechanic all I need is a cam and the sport would have a new engine. Head gasket and cracked head, it obviously overheated. It had 60 psi oil pressure at idle. The compression test w/oil was 150 across the port side and starboard was 100, 50, 100, 100. I bought a melling marine #24107 cam for the 78 and an edelbrock 2181 intake cause both intakes were rusted pretty bad. I guess I'm still on the fence trying to make an informed decision. That's why I brought it here. I do appreciate all the help and information.

Yes, that is all correct and there is still some lingering moisture in the crankcase of the 91 after 4 oil changes. That's why I decided to pull the engine in the 91. I pulled the oil pan from the 78 and looks like I need to remove the rear main cap to view crankshaft lines. I'll do that and report what I see.

Most engine overheats only damage the heads and head gaskets.  Unless someone really got stupid and heated the block till it scuffed pistons, if you see any dark verticle marks on the thrust side of the cylinders the block needs a rebuild.   If the cylinders are clean with good cross hatch still showing it should be good.

I installed the plastic strut bearings in my 95, no issues but I only have 125 hours on them so far.  There is very little drag in the shaft with the plastic  bushings.  I think they are made of Delryn same stuff used in human hip replacements and in ball joints on cars.

You were right about the helix lines and their direction. Looks like that's the only thing holding me back. Tomorrow I will try to get the engine out of the sport. I want to make sure it's a newer engine and has a 1 piece rear seal b4 I buy another crankshaft or have it machined. If I have it machined, will that require a different set of seals if they even make a seal for that application?

I'm trying to convert the 78 engine to standard rotation and put it in the 91 sport nautique. I have the cam, lots of break in lube, all the premium gaskets, new exhaust man's, ect. The wick or helix lines are my only issue.

I understand I can't use the crankshaft from the 91 because it has a 1 piece rear main seal. I'm still going to try to pull the engine out of the 91 sport nautique today just in case it's an older motor. My mechanic is looking for a standard crankshaft in case I need it. Thanks so much for all your help. It's great that you all take the time to help us make a more informed decision. I'm retired so I'm able to focus all my efforts on this project. I would also like to wakeboard at least on more time b4 it's too late. I have 6 grandkids that love to wakeboard too!