1997 L31 Vortec Install: Serpentine Setup Questions

[TheKorndog]

Been a hot minute since I’ve posted, but I’m back at it with my 72. I picked up a roller Vortec (the whole truck actually). I’ve scrubbed this forum to see if there was anyone who did a complete swap-as in, did you use the serpentine from the Vortec era motor (CPI/non-tbi/96-00 roughly)? And if so, how did it turn out? I see guys conversions and it’s awesome. I have the entire truck and everything is functional. Don’t intend on using the a/c out of it, I’ll do a delete.
Anyone do this style? Appreciate any info! Good to be back in it again-
Posted via Mobile Device

[truckster]

I used the complete serpentine system from the 98 that was the donor for my Vortec. No real problems. If you're using a stock-style hard fuel line with a mechanical pump, here's a post I wrote on how I did that:

https://67-72chevytrucks.com/vboard/....php?p=8823642

You'll need a reverse-rotation water pump (stock on the Vortec) and a reverse-rotation fan. The stock Vortec fan has a 19" diameter, and it won't fit in your fan shroud. I discovered that the fan from a 98 S10 4.3 liter is 17" and will just barely fit the shroud. I trimmed my a little for better clearance - I have about 1/4" all around.

My fan shroud was in pretty bad shape anyway, so I bought a new one from LMC. Then I cut it in half (top and bottom) and used joiner plates to put it back together. That makes it so you can actually access the fan without having to remove the radiator. I used an AC compressor from a 98, but an AC delete will work just as well. I also used the PS pump from the 98. If you remove the large fitting from the back of the pump, you can exchange it with the one from your previous pump, so the stock lines will work.

That's about it.

[TheKorndog]

Originally Posted by truckster

I used the complete serpentine system from the 98 that was the donor for my Vortec. No real problems. If you're using a stock-style hard fuel line with a mechanical pump, here's a post I wrote on how I did that:

https://67-72chevytrucks.com/vboard/....php?p=8823642

You'll need a reverse-rotation water pump (stock on the Vortec) and a reverse-rotation fan. The stock Vortec fan has a 19" diameter, and it won't fit in your fan shroud. I discovered that the fan from a 98 S10 4.3 liter is 17" and will just barely fit the shroud. I trimmed my a little for better clearance - I have about 1/4" all around.

My fan shroud was in pretty bad shape anyway, so I bought a new one from LMC. Then I cut it in half (top and bottom) and used joiner plates to put it back together. That makes it so you can actually access the fan without having to remove the radiator. I used an AC compressor from a 98, but an AC delete will work just as well. I also used the PS pump from the 98. If you remove the large fitting from the back of the pump, you can exchange it with the one from your previous pump, so the stock lines will work.

That's about it.

Posted via Mobile Device

[TheKorndog]

Appreciate the info for sure. I’m essentially taking the entire assembly from the 97, and plopping it in the 72. I’m using the 1406 that’s in the current motor and will probably use the electric pump w/regulator I have now. Big reason I’m asking is because the ac and alternator will be trading places, and I’ve still got the handy dandy external reg for the current 72 charging system still. I’m running an electric fan and such, so no worries there.

Sounds like you left the alt for the 98 on the pass side then? (Haven’t looked at your link as of yet).
Posted via Mobile Device

[truckster]

The AC is driver's side and the alternator is passenger's side.

[TheKorndog]

Originally Posted by truckster

The AC is driver's side and the alternator is passenger's side.

Yep, ultra clear on that So, are there any issues with the alt and ac pump on the opposite sides (wiring/master cyl location/etc). Did you run into wiring/fitment issues at all with the location change? Has it worked well? Also do you have a pic of your engine bay you could show?

Thanks for your replies, every bit helps
Posted via Mobile Device

[truckster]

Here's a picture of the engine bay. I rewired the truck completely because the previous owner had hacked everything up. The alternator wiring is easy, since it's closer to the battery. I used AC lines from a 98 S10, but my AC system is completely custom. There's no interference with the master cylinder, booster, or anything else.

[TheKorndog]

Dang, I may just go back to a/c. You made that look very simple! Quite a nice setup, and less apprehension to just jam it all in the 72 from the 97. I do appreciate the insight, I think I’ll move ahead with my plans.

One more thing, the single wire job from the internal mess. You use an adapter? I see you said you re-wired, was that included in the re-wiring job?
Posted via Mobile Device

[TheKorndog]

Originally Posted by truckster

Here's a picture of the engine bay. I rewired the truck completely because the previous owner had hacked everything up. The alternator wiring is easy, since it's closer to the battery. I used AC lines from a 98 S10, but my AC system is completely custom. There's no interference with the master cylinder, booster, or anything else.

Did you use the condenser from the 98 for this project?
Posted via Mobile Device

[truckster]

I used an EZ Wiring harness, but unless you really like figuring things out on your own, I wouldn't recommend it. The Painless or AAW kits are way more user-friendly. When I started the build I had a tighter budget than I do now, which is why I went with EZ.

The alternator is a CS130, which is stock in the 98 Silverado. It's not a one-wire; it has the voltage wire (the red one) and an exciter wire (the white one).

I started out thinking I would use the whole AC system from a 98 Silverado, and I bought all new parts. I was able to do some modifications to make the evaporator fit the 72 box really well, and everything looked really good until I tried to bolt the radiator support back on. The condenser was too big, so I had to go back to the drawing board. What I ended up with was a condenser and refrigerant lines from an S10. I had to rebend the lines just a little bit to get them to work, and I had to enlarge the hole in the radiator support to line them up. I'm just finishing the wiring inside the cab and hope to fire it up this weekend.

[TheKorndog]

Originally Posted by truckster

I used an EZ Wiring harness, but unless you really like figuring things out on your own, I wouldn't recommend it. The Painless or AAW kits are way more user-friendly. When I started the build I had a tighter budget than I do now, which is why I went with EZ.

The alternator is a CS130, which is stock in the 98 Silverado. It's not a one-wire; it has the voltage wire (the red one) and an exciter wire (the white one).

I started out thinking I would use the whole AC system from a 98 Silverado, and I bought all new parts. I was able to do some modifications to make the evaporator fit the 72 box really well, and everything looked really good until I tried to bolt the radiator support back on. The condenser was too big, so I had to go back to the drawing board. What I ended up with was a condenser and refrigerant lines from an S10. I had to rebend the lines just a little bit to get them to work, and I had to enlarge the hole in the radiator support to line them up. I'm just finishing the wiring inside the cab and hope to fire it up this weekend.

I’ll have to double check the alt for this 97. Seems like it had a single wire coming out of the pig tail connector and the usual red wire off the back. Thanks again truckster, appreciate your input and experience.
Posted via Mobile Device

[truckster]

Originally Posted by TheKorndog

I’ll have to double check the alt for this 97. Seems like it had a single wire coming out of the pig tail connector and the usual red wire off the back. Thanks again truckster, appreciate your input and experience.
Posted via Mobile Device

That sounds right. The small wire is the exciter and the wire on the terminal on the back is the voltage wire. Some have a second wire in the connector that's for a warning light.

[71meangreenc10]

I am using a 99 motor and figured out a few things with moving some parts around.

1. The 95 serp set up will work on the 99, just have to shim up the AC bracket and it all lines up. You will need a different belt to make it work. This puts the alt on the driver side and ac on the passenger side. I used the reverse rotation water pump from a earlier serp set up so the coolant lines work.

2. For the fan, if you are using a 2wd application, get a Big block shroud and you have no fan hitting issues. I am using a 05 Fan and different clutch. Can't remember right off the bat if the fan fits in the 2wd shroud with no rubbing.

3. I use the adapter for the alt plug and it works fine. I have one on my GMC and the alt has been running for years with no problems. I wont use the alt for the 99, I went with the one series before that one.

4. I took this pic before putting the idler back on. It works. If you use a 75c10 power steering hose on this set up, it has the correct bend for the pump and all you have to do is change the rear fitting.

5. This is all mock up parts, I have all new stuff for this motor and the heads just got back from the machine shop. I will run a 1406 and electric pump with a return line and regulator to keep the 1406 happy.

WP Pulley number- 10055880
Crank Pulley number- 10055879

Let me know if you need any info.

Smitty