I have a 89 F150 302, Lost # 7 piston melted a hole in the side of piston. Very little damage to top of piston could hardly tell what happened when piston was still in cylinder. Has a hole about the size of a dime in the side. We are not sure what caused this I have been told bad injector leaned out, vaccum leak, Burnt Valve Has anyone else had this problem. I am going to rebuild engine and dont want same problem with new rebuild.

 

Sounds like the cylinder ran lean and experienced some detonation. Most likely culprit is the fuel injector. Since you are going to rebuild, I highly recommend replacing all of your injectors. The stock 19# injectors can be had relatively cheap. I would also use different heads for the rebuild, nothing exotic. Best bang for the buck is to find some used edlebrock aluminum heads or GT40 heads. These can usually be found really cheap. Throw on some bolt-on 1.6 roller rockers and you will be smokin.

 

...... Since you are going to rebuild, I highly recommend replacing all of your injectors. The stock 19# injectors can be had relatively cheap. I would also use different heads for the rebuild, nothing exotic. Best bang for the buck is to find some used edlebrock aluminum heads or GT40 heads. These can usually be found really cheap. Throw on some bolt-on 1.6 roller rockers and you will be smokin.

Go here for all sorts of great stuff to accomplish the rebuild:

http://store.summitracing.com/egnsea...=KeywordSearch

Dart cast iron performance heads are available here:

http://store.summitracing.com/egnsea...=KeywordSearch