Any advice.

2003 4Runner 90K miles bought when new. Excellent shape besides the dash starting to crack. Just missed the deadline so will have to have replaced myself.

Have the dash I bought last year. Not sure yet if I want to attempt install.
And old one not real bad. Just starting to crack and knew I would get 4runner for at least another 10 years.

Already this will cost a fair amount. But thinking it could be a lot more if I dont do this. But am I over thinking this.

Is it worth it to replace the heater core and or evaporator coil at same time that the dash is already off. Is it common to have a problem with them?

Wife's car and only get used about 4K miles a year.

If recommended any idea how much more would cost to have replaced.

Thanks for any suggestions.