The more than 50 entries that showed up never got on track until almost 5 p.m. ET and were limited to about four hours due to persistent rain earlier in the day.
Former IndyCar driver Marco Amdretti led the way on the speed chart as teams focused on single car runs but once the drafting began after 8 p.m., Finch and his Venturini Motorsports teammates shined.
Finch, who is running most of the ARCA schedule this season, posted the top speed of 184.132 mph followed by his teammates Toni Breidinger, Kris Wright, and Gus Dean.
Three-time Supercars champion Shane Van Gisbergen, who is running a full NASCAR Xfinity schedule this year and a partial schedule in Cup, ended up 13th fastest. Van Gisbergen is running the ARCA season-opener in addition to his 40-race NASCAR schedule.
Saturday's test session saw two on-track incidents.
Amber Balcaen had a track bar mount break and hit the Turn 2 wall, which left significant damage to the right side of her No. 22 Toyota.
Sean Corr also had to be towed to the garage after he lost an oil line on track.
The two-day test will conclude on Saturday as teams are allowed to test between 10 a.m. and 5 p.m. ET.
Top 10 speeds from ARCA Testing Day 1
1. (#20) Jake Finch - 184.132 mph
2. (#25) Toni Breidinger - 183.989mph
3. (#15) Kris Wright - 183.955mph
4. (#55) Gus Dean - 183.756mph
5. (#17A) Marco Andretti - 182.371mph
6. (#6) Lavar Scott - 181.719mph
7. (#32) Christian Rose - 181.708mph
8. (#2) Andres Perez - 181.682mph
9. (#02H) Leland Honeyman - 181.631mph
10. (#18G) William Sawalich - 181.254mph
