You may also want to check your ignition timing since an advanced timing can lead to excessive noise - especially pinging when accelerating/under load. The factory spec is 5 degress Before-Top-Dead-Center, although, I have heard you can advance it to about 8 degrees BTDC to get a little extra "umphhh". There should be a sticker on the underside of your hood that lists the # of degrees BTDC for your truck.

'93 Pickup | 22R-E | 2WD| Yeah...it's my daily ride.