Blew a hole in my gen 4 5.3 aluminum block in my 08 Silverado. Blocks shot and I have a spare iron 4.8/5.3 lm7 sitting waiting to be bored or used. I was wondering if I can use the crank out of my gen 4 truck since it needs the 58x reluctor for the ecu in the gen 3 5.3? I know the sensors are a little different but they make extensions for them and I can buy a front timing cover for the front sensor. I don’t want to drill the block I just rather extend the harness and plug some if need be. Has anyone done this? I’m going to get new rods and pistons but want to keep stock crank but need the 58x. Called around my area not a lot of people remove or add the reluctor since you can buy a used crank or new motor for less. But he. 4 mins of hard to come by and pricey. I have a gen 3 already to go. Would my idea work or are there issues? I don’t see why not if I move some sensors around. Thanks

kevin

 

yes the cranks are interchangeable. Infact you can also just use the timing cover from your 08 also unless it had VVT
The biggest difference will be the knock sensors, You might even be able to just use the gen4 knock sensors on the gen 3 block, not sure if there is a hole in the correct location on the side of the block or not though.

 

There is no Hole on the side of the Gen3 blocks but you can drill one for them. The knock sensors types are different and not interchangeable. So you would need to modify the block and mount them some where.
Only other thing would be to plug the hole in the back of the block with an old cam sensor or buy a Billet plug from ICT.

 

thanks for replying guys i know the cranks are interchangeable i was just wondering about the knock sensors that are in the valley of the gen 3 and the side of the block for the gen 4. cant i just extend the sensor wires to reach the sensors in the valley and change the plug? im sure ict billet makes plugs for harnesses for this. but nobody has done it?

 

Some knock sensor use a different ?frequency? or signal, not sure how to word it. You might wanna check to see if there the same, if not you may be able to adjust for it in the tune.

 

You think the knock sensors would be different? I mean they are in different locations and possibly and may be different I’d have to check. So just the one crank sensor moves from back top of gen 3 engine to the passenger rear side? The cam sensor should be be an issue but since there are 2 knock sensors on the gen 3 are there 2 on the gen 4?

 

The cam sensor (not crank sensor) moves from the rear of the engine by the oil pressure sensor, to the front cover. You will need the timing cover from your 08 (if it doesnt have VVT) and a 4X cam gear witch you may already have.
The crank sensor will just need to be changed out for one from a Gen 4, it remains in the same location.

The knock sensors (2) are defiantly different. Maybe someone else can chime in to see if you can adapt a Gen 4 harness/tune to work with Gen 3 Knock sensors. Or if you need to find a way to mount the Gen 4 knock sensor to a Gen 3 block witch has been done.
Edit: a quick search on here confirms many people using Gen 4 knock sensors on Gen 3 blocks without tapping holes... you will need to adjust the sensitivity in the tune it seems.

 

Ok cool thanks so much for your help. Good info. I’m going to run a 4x 3 bolt cam gear because my afm was deleted in the gen 4 engine engine for a cam swap so I’ll be using the same cam maybe. It’s a Tr224. One issue I had with the gen 4 and deleting dod was oil pressure would go low under 20 psi even lower at idle then only go up to say about 40/50 psi when cruising. But when I start it from a cold start it would say 60 psi then slowly drop. I don’t think that was why it failed. but when deleting afm I didn’t cap the oil lifter towers in the valley. The valley cover I have has o ring plugs to cover it I guess. Anyways I know theres a bleed pressure relief in the gen 4 oil pans. I can run a gen 3 oil pan without the pressure relief thing in the pan? I think the relief valve was for when afm was activated it did something with the oil maybe? Not sure

 

Not sure on the pan Issue, but I dont think it matters once AFM is deleted. So not sure how a gen 4 pan works on a Gen 3, If your concerned with it just get a Gen 3 truck pan, there pretty much free.

If you blew a hole in the block (from a rod im assuming) I highly doubt your camshaft is still good, once you get it apart you will be able to tell, if it even comes apart.