"I'm sitting in a good spot but we've just got to have a good day.
"It might be a bit wet up there."
The V8 truck builder introduced a new truck for this series, which saw him victorious at round one on the Upokongaro course at Labour Weekend last year, despite not having time to test the vehicle before judge scrutiny.
While he would be the favourite to win the national title in Class D, Cowper said finishing on top of all the grades was the ultimate goal.
"The main thing we go for is overall. The class [win] is secondary.
"NZ1 is what we're fighting for."
This may involve a slightly cautious approach to make sure he doesn't have a big spill on one of the hill obstacle courses, while finishing in the Top 5 should be enough to win the crown.
"The last couple of rounds, we're feeling good about it," he said.
"As long as we don't do anything stupid."
At the February round in Masterton, Cowper's fellow Whanganui 4WD Club driver Kevin Hermansen won Class C and best overall, with Cowper second and Conwell third.
-Today's event is hosted by the Mt Egmont 4WD Club at 200 Hill Rd in Egmont Village, south of New Plymouth.
Action starts at 8.30am.