Factory Radiator / Heater Plumbing - '87 V20

[FoxCustom]

Hey guys,

Does anyone have the info. for the factory correct or proper way to route the cooling system in an '87 V20?? (My truck has the stock 350 tbi and I swapped from an automatic to a SM465.)

A seam on the bottom of my factory tank has a slow leak so I decided it was finally time to take care of it before winter with a new, aluminum Cold Case radiator. However, there are NO heater hose ports on this new unit.

Could or should I safely bypass the lack of ports directly to the radiator by running the heater hoses directly off the water pump / intake like a '50s setup?? If not, I'll stick with the factory unit and have it rebuilt but the current routing has no heater hoses coming off the water pump (strange I know). I do have great and very hot heat in the cab so I've never even questioned it.

Thank you!

-Zach

[geezer#99]

Do you have a pic of these ports?

[FoxCustom]

Originally Posted by geezer#99

Do you have a pic of these ports?

I’ll grab a pic of the current setup as soon as I get home.

I have read now that the pressure should come from a 5/8” port at the intake to the heater core and then return from the heater core to the 3/4” return on the radiator.

[FoxCustom]

Turns out I had gotten into a little bit of a panic about this!

The new Cold Case aluminum radiator had shown up by the time I got home today and everything looks perfect!!! The photo I was referencing on the site didn’t show the heater hose return port that I needed.

Also, my truck is plumbed correctly as seen in these photos - 5/8” pressure hose out of the back of the intake to the heater core, then 3/4” hose from the return to the port on the passenger tank of the radiator. All is good! I’ll post a pic of the finished install this weekend!

[FoxCustom]

Here are the photos of the current setup as well as the new radiator! (I’ll be running plugs in the trans line bosses as I’m running a manual trans now)

[geezer#99]

Good idea on the plugs.
Remember intake to bottom of heater core, top of core to rad.

[kipps]

Just curious, why did you go with the cold case radiator instead of one from rockauto or similar?

[FoxCustom]

As far as going with Cold Case vs. a “stock replacement”, I just figured the quality of the new replacement ones are not really that great and I wouldn’t compare it to factory. The truck had a 3 core brass tank unit in it when I bought it but I didn’t want to have the truck down for too long since it’s my daily. The cost of having the original radiator re-cored and tested balanced out to the equivalent of the Cold Case.

[FoxCustom]

Success with the install on Saturday, let everything sit overnight and gave the Hi-Tack and thread sealant a chance to cure and then filled it up Sunday morning. All good!!! Warmed up just like normal and it’s been running about 5-10 degrees cooler. I may actually switch to a stock clutch fan to help even out the temp a bit - it cools down quick! No leaks and nice, warm heat in the cab too!

[kipps]

That's a good looking truck! I've got a v20 as well. Someday mine might look half as good as yours.

Is the paint combo and trimwork all stock? Or has it been modified or dressed up any? Is the truck a Silverado?

Are those the stock hubcaps? I figured the '87 3/4 ton would have the six spoke pictured below.

Also, what's your rim and tire size?

[FoxCustom]

Thank you very much Kipps!

That paint combo is factory - my truck is a Scottsdale! I've dressed it up with repainting the wheels, 1" add-a-leafs up front, 255/85 Toyo M55's and the early 73-75 caps (I just prefer that shape for my truck)

Now that the truck is cooling so much better and effortlessly, I'm wanting to bring the temp up a bit... I'm planning to switch from a fixed blade / flex fan to a stock type clutch fan. It's getting colder here in Michigan so I want to bring the temp back up to 170-180 for better heat and efficiency.

[geezer#99]

I’d leave the fan alone and look for a winter grill cover instead.