At some point i plan on building a motor for my truck in the next year or so. I have heard that there are 2 different crank castings and that one was better than the other. I also heard the the higher quality casting only comes in the lightning and the Navigator. Is this true, what are the casting #'s and where do i find them. Questing # 2. Is there a block that is stronger than the other. If there is what did it come in and what are the casting numbers on it. Thanks

 

I heard the '03 block is stronger than the '02 because of the process they use to make it...but I'm not sure if it's true or not. I wouldn't worry too much about it, I've never heard of a Lightning block (or any block) being the weak point of an engine. It's all about the internals.

 

I read somewhere the '03 block - present has more webbing on it to eliminate possible flex or distortion.
so it is a little stronger.

as to the crank dispute changes through the the years? Who knows

 

well when you pull it apart you can look at the crank and see if it is forged or not, most likely it will be (i believe), and the 03 blocks being stronger is debateable. run a search

 

Here's a forged crank.

 

sal had posted a great pic of a cast and forged sitting next to each other, you could tell the difference of a cast by the casting line. casting line is thin, the forged line is a thicker line. ugh im confusing my self, but i assure you i know what im talking about

 

I know how to tell the forged from cast thanks though. What i meant was i heard there was there was 2 different quality forgings as far as the forged cranks go.

 

The part number for a forged is F75E-A17G.

If it starts with F7 then its the forged crank. Also The F indicates a 90's year part number and some 5.4 cranks I have come across from 98-99 have been forged.

 

Thanks man

 

any tuner imput would be greatly appreciated