If the tub is acylic, you can use a hole saw.
Most handles can use the 1 3/8" bit, the tub spout may need a smaller bit size.
The top side of the American Standard Caddet 5' whirlpool. I was hoping to have deck mount but not sure how to drill tub without the chance of cracking the tub, any info helpfull
Dave (not the plumber guy)
Be sure that the point where you drill the holes is reinforced for mounting the faucet.
Another thing that doesn't hurt is to use some masking tape on the tub - it marks eaiser and helps to keep the drill center in place. In fact, you may want to drill a pilot hole prior to using the hole saw - still use the masking tape. It also can help to keep the edges from chipping.
Important note - I'm not a pro
Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013