Best bet is to look at the current DRVSuites.com website to see if there is a floorplan for that model. Most of the actual lenths are 1.5-2 fit longer than the listed length.
The most popular 36' model was the TK3 (I have one) and I have never known what the T was for, but the K is for kitchen and 3 is for # of slides. But the 4th (br vanity) slide, if equipped) is usually not in the model number.
The Schwintek slide system was on 2012-13, mentioned lately in answer to same question. Easy to spot, the tooth gear bracket is at upper/lower area of both sides of bedroom slide. An '08 won't have that system, it will be hydraulic.
As to some advice--if you like the 36' model, might be interested in same floorplan in a 38'--makes some real difference in the living area.
Personal likes/needs are different for everyone, but I would not buy a unit that happened not to have the 12-13cu ft fridge--some of the 36' units have the 10 cu ft fridge that just does not have enough capacity for real use.
Some recurring problems over the years with DRV units: hard-to-pull/push black tank valve, will need to replace; trim screws that keep backing out during travel; 16" tires/wheels when 17.5" are needed to correctly carry load; heavy pin weights --need a dually pickup, even tho some pull with a SRW truck.
Lots of used units to look at-- rvtrader.com; craigslist.com; pplmotorhomes.com are a few to research for used pricing.
Also, I have most of the older year brochures--if you need something from one of them, just ask.
Good luck in the hunt.
2016 Tiffin 40 QBH
2015 38RSSA, traded
2005 TK3 #1869, 10 yrs of memories,
2017 F450 KR--one more Ford is it
2009 F450 4x4-died; 2010 F450-retired