Hi,

I got a decent deal on a 5.3 Vortec from a 2008 Tahoe with 65K miles on the engine and transmission (4l65e). The goal over the next few months will be to put it in my 1988 K5 Blazer. I've been doing a fair amount of homework on these LS swaps, but not as much information (e.g., videos, blogs, threads, articles) has been generated for late 80's Blazers and 4WD trucks - especially with Gen IV motors.

I'm planning on using the newer engine and transmission, but I'm keeping my 208 transfer case which requires an adapter [50-0405E from Advance Adapters] for about $280.00. I figure I'll buy the motor mounts from them too [713088-P] for about $80.00. From some of the information I have gathered so far, these are going to be the major problems I will encounter:

* High Pressure Fuel System is required for Vortec. I believe I can use my stock tank, but will need a stronger in-tank fuel pump. Any Suggestions? I'm also planning on using a fuel regulator/filter from a 2002 Corvet in order to adapt a return line. Doesn't look too hard or expensive so far.
*Drive-By-Wire Issues: Luckily, the 5.3 motor I'm buying comes with the electric throttle peddle, but I have only a vague understanding of how to hook it up. I haven't found any information on this yet. Any help would be greatly appreciated.
*Custom Wire Harness and flashing of TMC and ECM: Unfortunately, nobody local where I live is willing to do this, and electronics is something I know nothing about. I'm preparing for the punch in the pocketbook here, and will likely have to buy a $1,300.00 custom wire harness from Painless Performance (the flashing is included in the price). Does anyone else in the buisness do as good of a job for less?
*Headers that Fit: I've seen similar swaps with 81 and 84 trucks that have the same frame as my 1988, and all of the owners who swapped an LS indicated that the exhaust manifolds seldom clear the frame, and that the headers get in the way of things down by the transmission. I suppose I will not really know until I get into it. Any thoughts?
*Crossmember Issues:I'm anticipating that the 4l65E transmission will not quite match up or work with the stock crossmember. There are cheap universal crosmembers for 2WD 1988 trucks, but I haven't seen any for 4WD. These may work, but I think I will have to fabricate something or do some cutting on the original.
*AC Compressor: The folks at Painless Performance tell me that the new LS compressor will have to go, and that I will be using all the AC parts from my 88; however, the compressor will need to be mounted higher up on the motor with some sort of hot rod after market bracket. I've been searching Summit and Jeg's websites, but I don't know what bracket might work best. Of course March Performance has a $1,500.00 kit for the whole engine that will make it look like gem-crusted nipple tassels on a Broadway dancer, but I don't have that kind of cash or care for the aesthetic investment.
*Speedometer and Engine Gages: I'm pretty sure I have a speedometer cable, so I'll likely need to get the Cable X converter from Abbot (about $330.00) and the Painless Gage Control ($300.00) from Painless Performance to make the other original gages work. Does anyone know any other ways to do this that is under $600.00?

I think this is good start for now. Over the next few months, I hope to add lots of information to this thread that will address the issues I run into and make more useful information for other folks thinking about doing a project like this. Hope it will help, and I'm looking forward to all the help on this awesome forum.

 

The LS motor (with the transmission, transfer case, and pretty much everything else attached to the motor) was delivered to my house today. It looks a lot bigger in my garage than it did in the warehouse where I first saw it. I suppose this is more motivating to get the swap done sooner rather than later for the sake of space.

I removed the transfer case tonight and plan on selling it soon to get some of my money back and keep the motor clutter down. I managed to keep the AT fluid spillage to a minimum, but I'm having a hard time identifying what specific transfer case I now have. There are some factory stickers and bar codes on it, but nothing translating into a model. Does this look familiar in the pictures? Again, the motor is a 5.3, 4WD, automatic from a 2008 Tahoe with a 4l65E transmission.







Additionally, I've made some progress on the in-tank high pressure fuel pump issue. High Flow Performance has a fuel pump that they say will do the job with my existing tank and require no additional regulator. The part is HFP 255LPH Fuel Pump Chevrolet K5 Blazer 4x4 1988 - 1995 [SKU: HFP-343]. Holly has a pump that is fairly universal too, but High Flow's part seems better, and for $80.00, if it's all I actually need, then I'm feeling pretty good about the purchase.

Tomorrow, I'm planning on ordering the transfer case adapter, motor mounts, and I'll need to do a bit of work to the valve covers [looks like they slid upward just a notch when the previous owner pulled the motor from the Tahoe with a forklift.