So i have to get some valve work done soon. my l98 is jumping between 15-20"hg when i run a vacuum test. chances are I'm looking at either a bad valve, damaged seat, or carbon buildup. what I'm looking at doing is throwing some 2.02/1.60 valves in the stock heads then getting a decent bowl blend but first I want to know if this would require some computer tuning or not since the cam isn't being changed. car is a 91 With a 350 and speed density. I tried asking on ecu boards but haven't gotten any responses.

 

oh and I forgot to mention I do have an afpr so fuel pressure could be boosted a tad