I have a 1992 EFI heart shape head with pedestal mount rocker arm bosses. I want to install 7/16 screw in rocker studs to mount 1.7 BBC roller rockers. Question is about pedestal mount preparation.

Do I need to have the machine shop drill & tap the pedestal as they are and assemble only the number one piston/valves/springs to see if I need to remove any from the pedestal top and how much. Don't mine doing it a few times. I can also figure the correct push rod length to order at this time.

Or maybe there is a safe amount I can remove from the pedestal top the first time to get started. I will be running guide plates that are .140" thick.



Also has anyone out there used a Crane rocker arm guide plate conversion kit (52655-2 that installes a 7/16 rocker stud with the stud bottom threads 5/16 that go into a stock 1992 EFI pedestal mount. This is going on a ford 300 4.9L motor. This build is a mild over stock that will be in the 5500 max RPM range, with an RV cam & 1.7 BBC roller rockers. Spring rate is stock spec's, 9.0 CR with stock still D dish pistons and block milled .020". May make 180 HP if I am lucky.

 

You will have to at least mill the alignment slot off and drill and tap the existing hole.

 

There is no alignment slot on the 92 pedestal as seen in the attached photo. I will be drilling and tapping for 7/16 studs.

 

You might do better here:

https://www.ford-trucks.com/forums/forum52/