Serpentine Conversion

[Handy Andy]

Ok Gents, I'm getting ready to do my serpentine conversion on my 86 gmc k1500. I've picked up a donor 350 out of a 99 k1500. It was free so hopefully it will work. I can already tell that the idler pully needs to be replaced because it's loud as heck when I spin it by hand. I've got most of this stuff all figured out I think.

I've ordered an adapter to go from the si to cs alternator, I ordered it with a resistor because my truck has a voltage gauge instead of a dummy light. Rock auto has it for pretty cheap.

http://www.rockauto.com/en/moreinfo.php?pk=663890&jsn=284

The one thing on this that has me somewhat stumped is how to wire up the a/c. I understand that the clutch wiring should be a straight forward simple plug swap. What's getting me is the High pressure switch off the back of the pump. I should be able to just wire this up in series with the low pressure switch in the existing a/c system on the truck right?

The Red Rocket is undergoing a few decent changes this next couple weeks. I've recently swapped in a mini high torque starter rated for up to an 18.0:1 compression ratio so I will hopefully no longer have starting issues due to higher compression of the new motor and heat soak from running headers. Next is the serpentine swap which I will hopefully get finished up on Tuesday. After that, but probably at the same time as the serp swap I am going to swap out the old clutch fan for a dual fan ford Windstar setup I found at one of the local junkyards.

Anyone ever done a serp swap like this using the same 99 k1500 serp setup? Any pointers or tips?

 

[yevgenievich]

Best to get a new water pump instead of using one from the donor. Need a reverse rotation pump. Everything should be straight forward. High pressure switch should be correct if it is normally closed

 

[Handy Andy]

Right on, yea I was planning on getting the new water pump because of the reverse rotation. One question about that pump, it has 3 ports on it, 2 of which are on the top, the left one on the top is a bypass port right? I should be able to just plug that off and hook the rest of the hoses up the same as they come off my old pump right? Or should I just get a water pump from say an 89 model that has the same ports as mine, but is CCW for rotation. As long as it is a long water pump it should be right yea?

 

[yevgenievich]

Water pump from 87-95 should be fine as long as pulley position matches.

 

[bluex]

I'm doing this same swap on my truck right now. You'll need a pulley for the 88-95 water pump to. The center of the pulley is larger on the 96+ pumps.

That conversion plug is also for the larger 140A CS144 make sure you have that alt an the correct belt for it. If you don't have an alt consider a 99-05 AD244 it's a more reliable unit with a higher output at idle. It does take a different connector though. It is the same connector as the 105A CS130D that was commonly on the GMT400 pickups.

Oh an if you don't use the older water pump you'll have to plug that lower hole in the block. The vortec pump won't cover it since its bypass is internal. Since your buying a pump just get a 95 one. I got the GMB high performance one off rock auto.

 

[bluex]

Here's where I am at with mine at the moment

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[Honky Kong jr]

Looks good.

 

[1973c10]

Here's where I am at with mine at the moment

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very nice

 

[74 Shortbed]

Nice progress.

 

[Handy Andy]

I'm doing this same swap on my truck right now. You'll need a pulley for the 88-95 water pump to. The center of the pulley is larger on the 96+ pumps.

OK, so get the pulley for an 88-95 as well then. And if I use an 88-95 pump I won't have to plug anything off. Only problem I'm having is I can't seem to find a for sure match for a 95 k1500 water pump pulley. any ideas?

That conversion plug is also for the larger 140A CS144 make sure you have that alt an the correct belt for it. If you don't have an alt consider a 99-05 AD244 it's a more reliable unit with a higher output at idle. It does take a different connector though. It is the same connector as the 105A CS130D that was commonly on the GMT400 pickups.

I don't know which alternator I've got. I called up a local junkyard and asked if they had one for the vehicle that my donor motor came from, they said yep and that it had been tested and inspected to ensure it was good... $25 with a guarantee is pretty decent. If I gotta order a different connector then I guess oh well.

Oh an if you don't use the older water pump you'll have to plug that lower hole in the block. The vortec pump won't cover it since its bypass is internal. Since your buying a pump just get a 95 one. I got the GMB high performance one off rock auto.

 

[bluex]

The pulley is part # 10085760 for AC Delco. Its $46 though on rock auto. I would call the junk yard back it should be pretty cheap through them an any pulley from 88-95 should work. I'll post a picture of the difference between them later today.

Put up a picture of your alternator I can tell you which one it is.

 

[Handy Andy]

I haven't picked up the alternator yet. When I go on days off I'll go to the junkyard and pick up all the parts they have waiting for me. I'll also get to working on that pulley from the junkyard. My truck is truly going to be a Frankenstein truck hahaha. Gonna have to write a book about all the different year model parts that are going into this thing so the next owner will have a clue if I ever decide to sell it haha.

 

[bluex]

Here is the difference in the pulleys. The vortec one has a larger bolt pattern to so no chance of using it on the older pump even if the shaft bore difference didn't matter.

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[TRAZOII]

Ok, I have a question. I Have an 85 K10 Sub with a 350. What yrs and vehicles can I pull that pulley system from? Ive been told 88-94 4.3 v6 and also some gen 3 cameros and firebirds. Any specific ones work better for our trucks?

 

[bluex]

You can get most of the items from whatever vehicle you find. If it happens to be a V6 dont get the crank pulley though, that needs to come from a V8. I used a 96+ setup because I (along with many others) like the harrison style a/c compressors better than the pancake style R4 that comes on the earlier setups. As I mentioned above you can also use the AD series alternators which are more reliable than the earlier ones as well.

My setup will wind up spanning a few different year models but isn't difficult to remember an gives the best bang for your buck in my opinion.