Vortec 8100

[454cid]

The L21 would be a near direct bolt in for your L29. Just have to pull the timing cover and swap the reluctor out. Then put the L29 distributor cap on the L21s cam sensor body. Swap the valve covers and the throttle body and you would be good to go. L21 would be a helluva lot easier if you convert it back to run the L29s stock engine management.

That would kind of defeat the purpose of buying an L21... would it be that hard to get the L21 ignition to work?

 

[Christian Steffen]

I know the L21 would probably be simpler, but of the three engines I am looking at, it is the most expensive and just doesn't offer enough gain for the effort. I was already looking into an 0411 swap when the crankshaft broke so I had some of the information, but just hadn't made the connection to using it in the L18 swap. This really is no more complicated than doing an 0411 swap and adding a few wires. If the engine I am considering had come from a 4X4 suburban, I wouldn't even have to worry about that.

the more I think about it, the more I am leaning towards the 8.1 swap. There is no tuning involved other than sorting out the transfer case(and the wiring is already in my truck). By utilizing the ECM that came with the engine, it should run exactly the same it did in the donor vehicle. It simply won't know the difference.

As you said the accessory drive might be an issue. I would probably just install it without the AC compressor if it created an issue, until I managed to acquire or fabricate a bracket to relocate it. Ideally, I would copy the L29 accessory drive layout.

Can you post photos of your install, specifically the accessories. Without having my truck here I am seriously handicapped.

When you say doesn't need a tune, you just mean it won't be anything abnormal? I would recommend doing some improvements to the factory tune, I have no experience with the 8.1 but there is always room to improve on the factory tuning.

 

[Dahoyle]

Correct. I would still look into a tune down the road, but since the PCM is already tuned for that engine/transmission, it should behave exactly as it would in the donor vehicle. Basically, it would be plug and play if I chose to leave it alone.