Guide updates and tuning notes by email → Follow us
Plan a swap

Home › Q&A › Cooling

What electric fan setup works best on these trucks, and what radiator/fan combinations are compatible?

Start by measuring the radiator core you're actually running. Fan size and shroud depend on core height and width, which differ between classic and universal radiators.

Last updated

Pusher vs puller: a puller (between radiator and engine) is preferred — it's more efficient and it's what most OEMs use. Use a pusher (in front of the radiator) when there isn't room behind it, or to add airflow to an A/C condenser or cooler.

Single vs dual fans:

Single fan Dual fans
Pros Simpler, fewer relays, saves space, lower amp draw More airflow (high hp, A/C, heavy duty), staged operation, a backup if one fails
Cons May not cover a large core without a shroud; no backup Takes more space, needs a strong charging system and a relay/fuse per fan or a dual-fan controller, more wiring

Blade style: straight blades move a lot of air but are louder; curved "S" blades are quieter and are what most modern fans use.

Radiator + fan packages: direct-fit LS radiators (Afco, DeWitts, Frostbite) often let you pick a shroud with a single large fan or dual smaller fans. A big single fan may cover a square-ish core better, but its deepest point can end up closest to the engine, so check clearance.

What we recommend

For full-size trucks, what we recommend is the OEM 34-inch radiator with the OEM 05+ truck e-fan assembly, a Nelson Performance harness that ties into the factory harness, and a PCM tune to enable fan control so they work like factory e-fans. 05+ trucks came with 28-inch or 34-inch radiators, and the OEM 05+ e-fan shroud only fits the 34-inch radiator. With a 28-inch radiator, use LS1 dual fans or an aluminum shroud with aftermarket fans instead. If you tow long grades, keep the clutch fan in mind, since we've seen LS1/LT1 e-fans overheat on long climbs while towing.

Check this first:

  • Measure your radiator: 28-inch vs 34-inch
  • Confirm the PCM tune enables fan control
  • Use a good-quality harness; we've seen a PCMforLess harness burn up

Careful: A low-quality fan harness can burn up, and undersized e-fans can overheat a truck while towing.

Based on what we've seen work across our own builds, our friends' builds and the wider LS community, reviewed by our lead shop tuner (over 20 years of LS and LT tuning experience). Every combination is different, so use at your own risk and check our safe tuning limits before any wide-open pass.

Go deeper

Check this first

  1. Confirm radiator core width (28 vs 34 in) before buying fans

Try this, then this

  1. Junkyard 05+ fans + quality harness + PCM tune — OEM reliability. Worked if: fans cycle correctly

How you know it's fixed

  • Fans cycle via PCM; A/C pressures normal; no overheating in traffic

Still not fixed?

  • Check fan tune tables and relay wiring gauge

Every option we know of

Maker / productPart #FitsPriceWhereStatus / notes
Nelson Performance
e-fan harness		n/a99-07 trucksabout $100+nelsonperformance.comSmall batch
premium but well regarded
BP Automotive
e-fan harness (both low, then both high)		n/a99-07 trucksabout $150bp-automotive.comSmall batch
none reported
Amazon/eBay
bargain e-fan harness		n/auniversalabout $30AmazonIn production
melted relay plugs reported — avoid
GM
05+ truck e-fans		n/a

Prices are approximate as of September 2026. We list every option we know of, including small shops and used parts we can't link to. Confirm fitment with the seller.

Time and cost: 4-6 hours + tune

What radiator works best for an LS swap in a 72 GMC with A/C without stacking coolers behind the grille?
What we recommend

We recommend starting with a good single radiator sized for the truck rather than stacking coolers, and the stock-style route works: 67-72 stock radiators with a mechanical fan and stock shroud have cooled LS swaps with no issues, and an old brass/copper 4-row stocker does fine with proper fans and a shroud. If you want aluminum, the R&D Fabrication radiator is a drop-in made for LS conversions and includes a trans cooler at no extra fee, and it keeps an LQ4 cool. The Holley Frostbite and Entropy radiators have also held up well. Griffin gets mixed results; the Dominator 8-70013-LS ($268 at Summit versus about $220 for a stock replacement) puts both inlet and outlet on the passenger side, but we've also seen Griffin units leak within a few months. Whatever you pick, the shroud and fan setup matter as much as the core.

Check this first:

  • Core support fit (the Griffin 8-70013-LS is a smidge too tall for a 1967 core support)
  • Radiator width (a 2002 truck radiator is about 32 inches wide and won't fit)
  • Inlet/outlet locations versus your water pump and hose routing
  • Fan and shroud coverage of the core

Try this, then this

  1. Direct-fit aluminum radiator + shrouded fans — A/C adds heat load. Worked if: temps hold with A/C on

How you know it's fixed

  • Holds temp with A/C on in traffic

Still not fixed?

  • Verify condenser airflow and fan CFM

Key numbers

WhatValue
RnD Fabrication C10 radiatorsdual 1 in cores; LS versions with both ports passenger side + steam port

Every option we know of

We may earn a commission when you buy through links on this page.

Maker / productPart #FitsPriceWhereStatus / notes
R&D Fabrication
C10 LS radiator		n/a68-72 C10about $600-800was direct
may be defunct — confirm before ordering
Griffin
aluminum radiator		8-70013-LSC10 LSabout $500Buy
Summit		In production
verify PN fitment
Be Cool
direct-fit 67-72 C10 LS radiator		6031167-72 C10 LSabout $900becool.comIn production
Frostbite
3-row 67-72 C10 LS radiator		FB31167-72 C10 LSabout $500Buy
Summit		In production

Prices are approximate as of September 2026. We list every option we know of, including small shops and used parts we can't link to. Confirm fitment with the seller.

Time and cost: 4-6 hours

Something wrong on this page? Tell us