Advise Needed with Gen IV LS Swap

Hi,

I've got a complete 5.3 Gen IV motor and 4l60e transmission with low miles from a 2008 Tahoe that I am considering installing in my 1988 k5 blazer. I'm pretty familiar with the typical conversion issues for this swap (e.g., motor mounts, exhaust clearance, high pressure fuel, gauges, etc.). What I don't know about is whether or not the Displacement on Demand (DOD) with this new motor will become an absolute nightmare.

I have read a few threads on the DOD topic, as well as spoke to a few guys locally who build race cars and dyno tune. As of yet, I have no clear answers as to whether or not I should sell this engine and look for an LS without DOD. It looks like it might cause some serious problems for me. Does anyone have any experience with this issue?

I have no personal experience with DOD but it's not to difficult to eliminate it. I'd rather do that than try and sell it. Just my .02

Just set DOD to disable in HP tuners and move on.

I have clarified with two different professionals who flash PCMs and build custom wire harnesses that DOD/AFM on Gen IV engines is a feature that can be easily shut off without any sensor modification to the engine. From what I have been told, the only way AFM can still fail after being removed from a re-flash is if the AFM feature failed in some way prior to the re-flash. This makes me feel a lot better about using the engine I bought because, as far as I know, the AFM hasn't failed before.

So, I have a new question about designing the EFI high pressure fuel system for this engine. In short, I'm using my stock fuel tank and lines from the 88 Blazer because I presently have TBI for my original 5.7 Gen II motor, so I already have baffles in my tank, metal lines, and a return line. It has been said by others who have done ls swaps with similar blazers that a fuel pump from a Chevy pickup with a 5.7 engine between 1997-99 will drop right in to my tank and produce 58+ psi, but some folks say you need the fuel sending kit too, and others say that you do not. Does anyone know whether I would need a fuel sending kit too? New, they are very expensive (about $450.00). If I need it, I'll try my luck pulling one from a bone yard.

Thanks!

Got my Dirty Dingo motor mounts yesterday. I'll have to post some pictures of them on the engine in a bit. I probably will not be able to do the R&R until the second week of September.

Quote:

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Originally Posted by 88blazerboy

So, I have a new question about designing the EFI high pressure fuel system for this engine. In short, I'm using my stock fuel tank and lines from the 88 Blazer because I presently have TBI for my original 5.7 Gen II motor, so I already have baffles in my tank, metal lines, and a return line. It has been said by others who have done ls swaps with similar blazers that a fuel pump from a Chevy pickup with a 5.7 engine between 1997-99 will drop right in to my tank and produce 58+ psi, but some folks say you need the fuel sending kit too, and others say that you do not. Does anyone know whether I would need a fuel sending kit too? New, they are very expensive (about $450.00). If I need it, I'll try my luck pulling one from a bone yard.

Thanks!

Got my Dirty Dingo motor mounts yesterday. I'll have to post some pictures of them on the engine in a bit. I probably will not be able to do the R&R until the second week of September.

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AC Delco EP381. It drops right in where the current pump sits and runs up to 60psi and will flow 155lph. $58.85 from Amazon.
http://www.amazon.com/ACDelco-EP381-.../dp/B000C9SHOU

Thanks Skylark! I'll check the pump out. I sort of hit the bone yard today and pulled a pump and fuel sending kit out of a 1997 Suburban. I wouldn't dare use the pump, but if I needed the kit, I think it would suffice. I've never messed with fuel tank guts before, so it's all new territory for me.