Hello I was looking around for info. on these different years of 351w. Found one from June about this subject so that's why I'm making this thread. From the old school of when you wanted a water pump for a 292 it was no big deal. I'm in the process of changing engines in my 1987 F-250 4x4 351w carbureted. So I bought a used engine EFI from Craig's List (no water pump ) I was told the engine was a 1990. Bought a pump for 1990 and it fit. But reading different threads on this the rotation might be a issue. The 1987 has belts not serpentine. How can I figure out what year this motor is. Second can I get pulleys that fit or will the 1987 water pump pulley and such work on the 1990 water pump. Also the harmonic pulley. Also I'm getting rid of all emissions and staying with carbureted. PLZ HELP. THX David

 

The '90 engine would have been serpentine belt. Did the engine come with all the other accessories? If so, I'd recommend sticking with the serpentine belt setup. It's a lot less grief than the old style v-belt arrangement. Just get a new serpentine pulley for the water pump. There is nothing inherent in the block the defines it as v-belt or serpentine. It is strictly the pulleys on the accessories, and as you've found out, the water pump direction is different.

 

THX for the replies, not knowing that there was any difference in the parts. I mounted the timing cover and new pump, so I will stick with the serpentine setup. So I will need a new pulleys for the water pump, balancer, alternator, power steering pump and idler, and tensioner. Or would it be cheaper to us the parts off of my 87 and buy new water pump and seal. The 87 has mechanical fuel pump. Boy I got myself into this hole, but I'm learning. Where does one buy these pulleys? THX David

 

I would go to a salvage yard and pull off all those parts from a vehicle with the same engine. IE, pull the actual accessory parts (alternator, PS pump, AC compressor, and smog pump if you need) so you don't have to mess with removing or installing the pulleys. The water pump is about the only thing that requires little effort to change the pulley on. In addition to the idler and tensioner pulley assemblies, also get the mounting brackets for all these parts.

It might be easier to turn that 1990 engine into a 1987 by using all the old engine's accessories.

 

THX, XLT4wd90 I'm leaning towards that direction. Just wanted to keep driving the 87 as long as possible because it will take me awhile to complete the change. I will just be out the new water pump cost. I'll try and sell the pump and timing cover on Craigs List. THX David

 

You would have been better off using everything off the 87 motor. Timing cover, water pump, pulleys, alternator, etc. The 87 and 90 had different timing covers, the 90 being for a reverse rotation pump the 87 with V belts a standard rotation pump

 

You are right on Baddad457 I'm learning that the hard way. Put the timing cover from the 90 back on bought water pump put it on. Now I'll have to remove and have parts can't use. I'll try and sell. THX David