4.8 pistons

[Drok]

underdrive pully

I keep seeing underdrive pullys on the Web anyone have them and are they with the money?

 

[ccapehartusarmyINF.(ret)]

yes it definatly needs a tune
the overall size of the 4.8 and 5.3 motor is the same but when you swap 4.8 with 5.3 pistions your increasing the engines displacement and compression ratio a 4.8 has aa 9:1 compression ration and 292 ci of displacement now when you put in the 5.3 pistons wich are probably shorter then the 4.8 pistions wich would increase the displacement to 323 ci and probably give it a 10:1 compression ratio assuming the 4.8 and 5.3 heads are the same