Alright, so I spun a rod bearing and am in the process of rebuilding it, I found out that my block is cracked at the water jacket on the head. I've found an LT4 that just blew a headgasket for cheap, but I'm curious if the heads are warped or if the block is cracked. Also I've found someone to rebuild me long block using my H/C. What should I do? Risk the LT4?

 

So which is cracked? The block or the cylinder head?
If your block is cracked, throw it away. If the head is cracked it can be repaired. If you don't want to go that route then by all meands get the heads, but take them to a shop and have them checked to see if they need to be milled. Even if they are warped they may not have to be milled all that much. They can also pressure test them to make sure there are no cracks in the water jackets.

 

It cracked right where the head sets on the block, so its toast. I think I'll get the LT4 and just get the block magnafluxed before I assemble it. Although it doesn't come with an intake and I'm not sure if my lt1 intake will work on the LT4 heads.

 

You cant mix lt4 and lt1 heads and intakes. 2 of one or 2 of the other.

 

Are the LT4 heads really that much better? Would it be worth looking for an lt4 intake or buying a new one? Or should I just stick with the LT1 heads and intake.

 

Just throw your heads back on it or have the LT4's worked and then do a head and cam swap down the road or you will need an LT4 intake Stock or The air gap one. By the way I would have that block gone through and just rebuild it and get it ready to make power or rebuild it stock. You shouldn't trust other people's ****. I have been burned and so have many others. It's worth a trip to a good builder to let him go through it and see if it is in need of a rebuild or not.

 

I was planning on rebuilding that LT4 anyways, it has 100,000 miles on it and I figured its just a good idea. It already has a mild cam so I figured its worth it just for the H/C for the price I'm paying even if the block is screwed.