This isn't for a truck but for my 1994 Cobra. What started this build is when I broke another rocker arm and bent another pushrod. It was the second time that it happened. The first time was about 20,000 miles prior. With 90,000 hard miles I figured the cause was weak valve springs. So I pulled the heads and and while I had them off ported them. I then took them to Pacific Engine and had them machined and a valve job done. While doing so they discovered that AFR had way too much spring pressure and that some of the springs only had .500 lift before going into coil bind. My cam with 1.7 rockers has .530 lift so it's surprising they lasted 90,000 miles.
Here's the broken rocker.
Here are some of the porting work I did on the...