Do you mean the MP .484 cam ?? I just have not heard of a MP .488 cam but I may be wrong myself and just not up to date on them. Myself I used the MP cams a good bit over the years and I found I liked them all in my combo's but like any combo you just have to get the full combo right. Many stick a .484 cam in a stock 383 with 3.23 gears and a stock converter and then say the cam is no good. Yea right its the cam. But anyway in a basic reply if the eng is modded some and it used the AVS on it in stock condition then it will most likey need some jet change. Best bet in todays world is put an 02 sensor setup on it and then you see just what it needs. I came up doing it the old school way in the 70's to determine jetting but in todays world its best to take advantage of the technology we have and install the 02 sensor setup. Then you can jet for good performance and mileage. Ron

How does the car run right now when you lay into it ?