GNXClone

iTrader: (7)

I don't have a Gen-III valley cover in-hand to play with, but I am assuming it won't fit a Gen-IV engine because of the AFM/DoD risers in the Gen-IV engines' valley?

I have an LS7 that I want to put into a '99 truck which currently has a 5.3L.

I know that some people have relocated the LS1 knock sensors to the side of the block by drilling, tapping and extending the harness, but I don't trust sensors tuned for the valley cover to work on the side of the block. And I most definitely do want to retain the sensors.

The risers in the LS7 block's valley have not been drilled. So I'm wondering, can I simply have these milled out so that I can use the Gen-III valley cover, keeping the knock sensors in their original location?

This LS7 already has a 24x reluctor, and wet sump oiling. The knock sensors are my only hold up.

S10xGN

iTrader: (11)

Covers don't interchange, the bolt pattern is different. Haven't seen inside the LS7 valley, but it's likely there's no bosses to bolt a sensor to. Why not use the block bosses on the LS7 as intended and extend the wiring harness?

GNXClone

iTrader: (7)

Good information! Never having had a Gen-III, I didn't know that. I also didn't know the sensors bolted to bosses that were part of the block, but that does make perfect sense.

I have read that using the Gen-III sensors on the side of the block doesn't work, or doesn't work very well. I can believe it given that they are designed to be placed elsewhere. But it seems like it's either that, or don't use them at all.

Thanks for the reply, it was very informative!

XtraCajunSS

iTrader: (2)

We've done over a hundred swaps of Gen IV into Gen III cars. We've always used the knock sensor extension harnesses and relocated them to the sides of the block. Based on actual testing with the knock sensors in both locations I've seen no detrimental effects with relocating them. They do register knock very well on the outboard locations.

Thanks,
Shane

S10xGN

iTrader: (11)

BTW, here's what the later style "side mount" sensors look like...

Steve01SS

iTrader: (43)

Also, the oil pressure sensor bolts the the block on the gen 3. The gen 4 it bolts to the boss on the valley cover.

XtraCajunSS

iTrader: (2)

Just to be clear, the "new style" knock sensors mentioned above will NOT work with an early style 24X computer. You must use the knock sensors which originally came with your car/computer.

Shane