^
I’ll give my same speech on save mod money and use it to auto-X and track days. Not only will your car get faster, because you drive better, but it is a “mod” that you can take to any car you drive.
Cams are relatively easy to do for a OHC car.
IMO it is pretty much a waste to build a NA Sentra for power, unless you have something down to 2200 pounds and have a VE in it.