CamperResearchFind your rig →

Heartland Milestone 377MB

Fifth wheelbuilt 2019–25Mixed build tierCommon on the used market
WHAT ONE COSTS
$72,800est. used (2025, 1 yr old)

Sticker was $101,071 in 2025. Out of production since 2025, so the used market is the only way to buy one. Estimate assumes a 2025 unit.

WHAT IT WEIGHS BEHIND YOUR TRUCK
~13,728 lbestimated as towed, for 2 people

dry weight 12,511 lb + fresh water (50 gal, full) 417 lb + propane + battery 200 lb + gear for 2 600 lb. Brochure dry weight omits water, propane, batteries and your gear; this estimate doesn't.

You want a tow rating around15,255 lb (10% margin)
GVWR (the sticker maximum)15,000 lb
Tongue weight, loaded~2,774 lb (20%)
Cargo capacity2,441 lb
WHICH TOW VEHICLES IT FITS: 19 OF 95

Judged the way the app judges: estimated loaded weight against each vehicle's rating less a 10% margin, per model year, because the 377MB's published weights changed mid-run. Fifth wheels also need a pickup bed and are held to the fifth-wheel rating where published.

VEHICLETOW RATINGVERDICT
Chevrolet Silverado / GMC Sierra 2500HD (Duramax, max tow) '24-2622,500 lbfits, loaded, with 10% margin
Chevrolet Silverado / GMC Sierra 2500HD (Duramax) '20-2318,510 lbfits, loaded, with 10% margin
Chevrolet Silverado / GMC Sierra 2500HD (Duramax) '11-1918,100 lbfits, loaded, with 10% margin
Chevrolet Silverado / GMC Sierra 3500HD (Duramax DRW, gooseneck) '20-2636,000 lbfits, loaded, with 10% margin
Chevrolet Silverado / GMC Sierra 3500HD (Duramax DRW, gooseneck) '11-1923,300 lbfits, loaded, with 10% margin
Ford F-250 Super Duty (6.7 diesel, gooseneck) '20-2222,800 lbfits, loaded, with 10% margin
Ford F-250 Super Duty (6.7 diesel, tow pkg) '17-1918,000 lbfits, loaded, with 10% margin
Ford F-250 Super Duty (6.7 diesel) '11-1616,600 lbfits, loaded, with 10% margin
Ford F-250 Super Duty (6.7 HO diesel, gooseneck) '23-2623,000 lbfits, loaded, with 10% margin
Ford F-350 Super Duty (6.7 diesel DRW, gooseneck) '17-1932,500 lbfits, loaded, with 10% margin
Ford F-350 Super Duty (6.7 diesel DRW, gooseneck) '20-2237,000 lbfits, loaded, with 10% margin
Ford F-350 Super Duty (6.7 diesel DRW, gooseneck) '11-1621,600 lbfits, loaded, with 10% margin
Ford F-350 Super Duty (6.7 HO diesel DRW, gooseneck) '23-2638,000 lbfits, loaded, with 10% margin
Ford F-450 Super Duty (6.7 HO diesel DRW, gooseneck) '23-2640,000 lbfits, loaded, with 10% margin
Ram 2500 (6.7 Cummins HO) '19-2620,000 lbfits, loaded, with 10% margin
Ram 2500 (6.7 Cummins) '11-1817,980 lbfits, loaded, with 10% margin
Ram 3500 (6.7 Cummins DRW, gooseneck) '13-1831,210 lbfits, loaded, with 10% margin
Ram 3500 (6.7 Cummins HO DRW, gooseneck) '25-2636,610 lbfits, loaded, with 10% margin
Ram 3500 (6.7 Cummins HO DRW, gooseneck) '19-2437,090 lbfits, loaded, with 10% margin
The 76it doesn't fit

These verdicts assume 2 people aboard with typical gear. See the margin for your truck and your crew →

THE SPECS
Length42.9 ft
Height (incl. A/C)13.5 ft
Width8.1 ft
Interior height6.5 ft
GVWR15,000 lb
Dry weight12,511 lb
Dry tongue weight2,528 lb
Cargo capacity2,441 lb
Sleeps8
Slide-outs4
Axles2
Fresh water50 gal
Grey water80 gal
Black water80 gal
Air conditioning15,000 BTU
Awning16 ft

A missing row means the maker never published that figure: unknown, not zero.

WHERE PEOPLE SLEEP
  • 1× Queen bed, front bedroom(Permanent)60×80
  • 2× Mid-bunk beds(Permanent)—
  • 1× Tri-fold sofa(Convertible)—
  • 1× Booth dinette(Convertible)—
HOW IT'S BUILT: 5/5
WallsAzdel composite
FrameAluminum
RoofWalk-on
UnderbellyEnclosed

Heartland (Mixed tier): Milestone

YEAR BY YEAR: WHAT CHANGED
YEARSGVWRDRYMSRP
2019–2115,000 lb13,065 lb$74,209
2022–2515,000 lb12,511 lb$101,071
  • 2019Introduced
  • 2026Dropped in the Milestone relaunch
FINDING ONE

Common: usually several for sale within a day’s drive. Why: Heartland is a volume manufacturer. Estimated from build volume and production span, not a count of live listings.

OUR TAKE

The family mid-bunk Milestone: private bunk room amidships, big 80-gal grey and black tanks.

OTHER MILESTONE FLOORPLANS
310RK · 15,000 lb · sleeps 4317RL · 15,000 lb · sleeps 631RL · 14,800 lb · sleeps 4321FL · 15,000 lb · sleeps 4326RL · 15,000 lb · sleeps 4333MB · 15,000 lb · sleeps 6360HP · 15,000 lb · sleeps 4360RD · 15,000 lb · sleeps 636RK · 16,000 lb · sleeps 2370FLMB · 15,000 lb · sleeps 4379FLML · 15,000 lb · sleeps 8380DSL · 15,000 lb · sleeps 8386BH · 15,000 lb · sleeps 8387RBH · 15,000 lb · sleeps 8the whole line →
Find one for sale

Live listings for the 377MB on the big marketplaces. Each search opens pre-filled with this exact floorplan:

RV Trader ↗Camping World ↗FB Marketplace ↗Google ↗

Inventory varies by site and day. Slim pickings? search the whole Milestone line ↗

Is the 377MB your #1, or just a spec sheet?

These are the facts. Whether it beats the other six thousand rigs for you depends on what you care about. Set your priorities as sliders, switch on your hard limits, and watch the whole market re-rank around them. Every exclusion explained, every margin shown.

See where it ranks for you →

Data compiled from manufacturer spec sheets, retrieved 2026-07.