Newbie question

[Aloha Truck]

Bought a 70 blazer with a 3.73 rear a with both engine and transmission shot. Plenty of rust etc but it looked liked it needed a home and as some people save dogs and cats I thought I would take her and find a new engine and tranny. Long story short it now has an 2005 Escalade engine with 150k on it along with the matching Escalade tranny from just Chevy trucks.com. The problem is the only way to keep the 4wd is to keep the truck in 4wheel high and when I need 4wd just hop out and turn the hubs. My question is will keepin it in 4 wheel high 99 percent of the time hurt the tranny or engine or front axle? It’s my first truck so excuse my ignorance