Hi bro jerrylam. Yes there is another race next week Noobie is going too i.e Viper Challenge (12km at Iskandar on Sat morning) + Borneo Marathon (fly out from Senai after that) b2b. Noobie needs to work on upperbody workout hence the added obstacle race in the morning.
But even though Noobie already signed up, there is another trail race up north which is equally if not more interesting i.e King of Kampung Kemensah (50K). Both races' medals are by Medal Depot (yay!). This year Noobie aiming for more trail races.
Maybe you can consider also bro jerrylam. Saw that u going Bangkok for ATM Bangkok Marathon (congrats!) and I think Borneo by flight can also be a simple weekend runningthon.
While attempting 161-km in 32 hrs does not sound so hard in theory (about 5km/hr pace), its totally diff in reality and many learned this the hard way in the first 2 editions of Craze Ultra when the number of finishers (100 miles category) was <25% of those who started. 8 months to prep for a 100-km will be sufficient though. Do consider the 100km first bah.
The 100km can be used to qualify to ballot for the Western States 100 miles race too as long as you finish it within 22 hrs (which is still a reasonable goal).
The B2B God has spoken!!! Yes, this will be a good B2B challenge for you. Not forgetting Sundown is also 2 weeks away. If there's another race the following week after 50 hours, it'll be an interesting April for you.