I read that if you use guide plates you're supposed to use hardened pushrods. I also read that my 305 heads don't need guideplates because they already have somewhat of a guide already in the head. So if i was to put guide plates on my heads anyway, would i need to replace my pushrods or are they already hardened.

 

stock pushrods arent hardened. correct me if im wrong.

 

The slots in the head serve the same purpose as the guideplates. The pushrods have to be hardened to keep them from being worn through. Non-hardened pushrods can only be used with self-aligning rockers and no guideplates or slots in the heads.

 

only one type of pushrod alignment should be used, either the slotted holes in the heads, guideplates, or self aligning rockers, not 2 or 3 at a time.

 

I'm not going to use more than one. I'm going to use guideplates and drill out the old guide holes. I wouldn't have bothered doing it but my engine machining teacher told me i needed guide plates before i realized the heads already had guides. Its just as easy to go ahead and use them as it is to send them back.