I had a truck just like this with a 671 dyers blown stroker 340. I Got beat by a diesel twice as heavy.My my own truck with my son driving none the less. I converted it to a diesel using a 93 diesel cab and a 2004 diesel motor. What a difference in power. The truck posted above looked excactly like your short bed. Heres some pics when I used it to tow and then when it was blown. and during the diesel swap.