39FL: five slides and the heaviest pin in the family
Two figures single out the 39FL. RVUSA's 2026 guide lists five slides, one more than any other Bighorn, and Heartland's spec table gives it the heaviest hitch weight of the seven, 3,090 lb, which is also the highest pin share at 19.8%. The 38RE, on the same 17,995 lb GVWR, puts 120 lb less on the pin. The 39FL also has the thinnest margin between GVWR and unloaded weight, 2,350 lb, so a buyer shortlisting it should check truck payload before anything else. Heartland prints that 2,350 lb as the plan's cargo carrying capacity, 650 lb less than the 39RK's 3,000 lb.
Its tanks are the only matched pair in the lineup: 74 gal gray and 74 gal black, 223 gal with the 75 gal fresh tank. Five Bighorns carry a 50 gal black tank; the 39FL's is 24 gal larger. It is rated for 4, lists 8 ft 6 in of main interior height, 1 in under the 39RK and 40DB, and stands 13 ft 3 in with the air conditioner, 3 in under a 13 ft 6 in limit.
The layout question is one the available drawing cannot answer. Heartland's 2026 brochure prints the 39FL too small for its labels to be read, and there is no current Heartland page for the plan. The FL in the code reads like Heartland's shorthand for a front living room, and a living room in the front section would sit over the pin. Is that where the extra slide and the extra pin weight come from? The brochure does not say, so the unit has to answer it.
Heartland's 2026 Bighorn brochure, spec table and equipment list →The 39FL at the far end of three Bighorn columns
39FL specifications from the 2026 brochure
Bighorns to weigh against the 39FL's five slides
Each is within 7 in of its length or shares a key rating. Room details come from Heartland's current drawings of those plans.
1 ft 4 in shorter and 370 lb lighter on the identical 17,995 lb GVWR, with 120 lb less on the hitch and one slide fewer. Heartland draws its lounge at the rear around a TV lift and fireplace, its 137 gal gray tank is 63 gal larger, and it also sleeps 4.
Open record →Rear kitchen and the largest marginBighorn 39RK7 in shorter, 445 lb lighter, and 130 lb lighter on the hitch, with GVWR 205 lb higher and two slides fewer. Its 3,000 lb margin is 650 lb more than the 39FL's.
Open record →Same 43 ft 10 in, rated for 8Bighorn 40DB465 lb heavier with GVWR 855 lb higher, yet 165 lb lighter on the hitch and one slide fewer. It sleeps 8.
Open record →Four things to confirm on a 39FL before trusting the numbers
- Walk the unit from the pin end to the rear and note which room sits in the front section. That answers whether the FL means a front living room and what is riding over the 3,090 lb pin.
- Count the slides, then close all five and walk the same route. With more slides than any other Bighorn, check which rooms stay usable with everything in.
- Find the king mattress, listed family-wide at 72 by 80 inches, and the washer and dryer prep, and note how far each is from the bath.
- Read the unit's weight label. With the smallest margin in the family, 2,350 lb, any difference from Heartland's figures matters, and the brochure notes that some specs may include estimates.
Sources for the 39FL, and what they leave open
Figures come from the spec table in Heartland's 2026 Bighorn brochure (Rev. 2/26), last checked here on 2026-08-15. The slide count is from RVUSA's 2026 spec guide. The brochure's drawing of this plan, read on 2026-09-26, is printed too small for its labels to be read, so this record describes no room positions, and reading FL as a front living room is this site's inference from the code, not a Heartland statement. The mattress and washer and dryer items are from the brochure's family-wide equipment list. Heartland footnotes that some specs at the time of print may include estimates; the label on the unit governs.