In the process of swapping a 5.7 in my YJ to replace the old and tired 2.5. Have the '97 5.7 vortec out and on an engine stand. Painted, cleaned and replacing some accessories, sensors, etc. I took the MPFI cover off and the intake has a lot of built up black carbon. Photos below. Interesting because it looks like most of the build up is only on the front end more than the back half. What should i reasonably do since i am this far to clean this? Should i even clean it? I don't want to take the entire intake off if i can help it. Also want to be careful to not cause problems down the road and drop a bunch of scrapings into the intake. First engine swap I am doing and it was a great motor coming out of the old family Suburban.

PS - Yes, i'm putting on new valve covers so excuse the messy paint.

 

If you're not going to pull the intake I would do nothing. This is normal and I wouldn't worry about it.