Munster held strong Friday in the state swimming prelims in Indianapolis, while Chesterton and Valparaiso faltered.
The Seahorses stood pat or increased their seeding for every championship heat except the 400-yard free relay for Saturday's final heats.
Munster remains the fourth seed in 200-yard medley relay (1 minute, 31.82 seconds) and Grant Afman seventh in the 100 butterfly (50.03). Holden Raffin moved up three spots to seventh in the 200 individual medley (1:50.57) and a spot up to fourth in the 100 backstroke (50.01). Kyle Adams moved up a spot and is seeded third in the 100 breaststroke (54.71).
The 400 free relay dropped five spots to eighth (3:09.49).
Chesterton's Andrew Alders entered the prelims as the top seed in the 200 IM, but he fell down to the consolation heat in ninth (1:51.72). He dropped two spots in the 100 fly and is now seeded fourth (49.6).
Teammate Nick Hanas dropped three spots in both the 500 and 200 free and is now seeded sixth (4:33.12) and seventh (1:41), respectively. Lucas Piunti fell six spots to 11th in the 200 IM (1:52.2) and three spots to 11th in the 100 back (51.33).
Ethan Wing moved up four spots in the 100 free to qualify for the championship heat in seventh (46.51).
The Trojans moved up a spot to sixth in the 200 medley relay (1:33.96), down four spots to in the 200 free relay (1:25.97) and down a spot to third in the 400 free relay (3:07.12).
Valparaiso entered as the top seed in the 200 free relay and fell 10 spots to 11th (1:26.27). Ryan Hrosik dropped 10 spots to 13th in the 100 fly. He dropped one spot to third in the 50 free (20.45).
Highland's Ethan Churilla remains fourth in the 50 free (20.46) and dropped one spot to third in the 100 free (45.21).
Diving prelims start at 8 a.m. Saturday and finals begin at noon.
Merrillville 70, Penn 64: The Times No. 1 Pirates (17-7) got 28 points from Johnny Bernard, 13 from Jayon Holmes, 12 from Rob Sanders and 11 from Braedan Stubbs in the road win over the Kingsmen.
Munster 78, LaPorte 42: Tyler Zabrecky scored a game-high 19 points to lead the Mustangs over the Slicers.
Eric Jerge added 12 points for Munster, while Jevon Morris added 11.
Garrott Ott-Large had 15 points for LaPorte. Austin Haferkamp added 10.
Calumet 63, Highland 54: Davion Brooks scored a game-high 19 points to lead the Warriors over the Trojans.
Jaylen Sullivan added 17 points, while Jacori Gillespie had 10.
Tyler Scheidt led Highland with 16 points, while Isaac Sytsma had 10.
Kouts 66, LaCrosse 51: Zac Normanson scored a game-high 18 points to lead the Mustangs (11-11, 5-2) over the Tigers (8-13, 1-6) in Porter County Conference play.
Brent Wireman added 13 points, while Dillan Matthes had 11.
Wes Brust had 13 points for LaCrosse. Hayden McDougal had a double-double of 10 points and 10 rebounds.