289 hipo rockers

Quote from mycarisfast

I have a 289 hipo engine in my mustang, the heads have slotted pushrod holes, only my exhaust rocker arms are railed, I was curious about this and the pushrod length. thanks

With slotted push rod holes, you are creating an interference with rail rockers. Rail rockers were never used on Hipo 289 engines. The valve stems for rail rockers are longer to keep the rockers from rubbing on the valve spring retainers. You will need to change the valves if the ones in the engine currently are of the longer type. You can easily tell just by looking at the space between the valve spring retainer and the top of the valve stem. That should be the same for all of the valves. There is a chance of that current bad setup to cause the valve spring retainer to come off and drop the valve. Very expensive fix.

The original push rod length is 6.825.

-Fred-