K5 Blazer Swap Questions

[C.I.Blazer]

I have been looking at engine/drivetrain options for my 71 Blazer and really like the idea of an LS swap for my intended use of the vehicle. I have been reading A TON on this forum as well as LS1Tech and must admit it is a lot to absorb. I think it is also challening because so many of the swap threads are on 2wd vehicles and many are very old. I know there must be a lot of new ways to make this swap easier.

I am trying to break down the project into 4 or 5 sections to help me get a handle on what needs to be done.

1) Physically fitting the motor and transmission into the vehicle with the appropriate mounts.

2) Providing a fuel system.

3) Purchase harness (more likely than reworking my own), engine wiring, and tuning the ECM. This would include DBW pedal.

4) Deal with all the accessories (e.g. alternator, water pump, headers / exhaust, air intake, radiator, power steering).

5) All the remaining miscellaneous items like gauges and ???

Does that seem about right?

I am tackling number 1 first and had some questions I am hoping for some help with. My goal is to leave the NP205 in the stock location and not have to redo any drivelines. In order to accomplish this I plan to use a 4l60e (currently has a TH350) and the Advance Adapters kit to mate them together. My understanding is that this should move the motor 1-2" forward.

To accommodate the engine moving, I plan to us either the Dirty Dingo (most likely) or Pacific Fabrication engine cross member and adjustable motor mounts. This should give me the space I need for the longer tranny but still leave me room for the water pump, fans, etc.

Does all this make sense? What am I missing or not thinking about.

Also, I am really having hard time finding a motor with under 200k miles on them. I am only searching up to 2006 because I have heard the gen 4 (LM7, LQ4, or LQ9) is an easier swap than the gen5. Any tips on where to look? Should I be looking for something newer?

Thanks for the help.

[mongocanfly]

sounds like you have a plan that should work...
if you can leave to 205 in its current spot and make it work then great...but I wouldn't be committed to it until you get the whole unit in place and see what you got..you may need to move it front or back to clear...driveshaft work isn't that bad expensive
youll just have to keep looking for a engine..but keep in mind your looking for 15-20 yr old engines,,,be hard to find one low mileage....I wouldn't be scared of the newer engines...or throw a rebuild on what you can find
the stock accessories should be ok
you may have oil pan clearance issues...I used a vett oil pan on mine to give more clearance on the front diff

[C.I.Blazer]

Thanks Mongo. That makes sense. I guess I just want to keep the NP205 in the same place to stop the snowball this project has become. But you are right. In reality I will just but the whole setup where ever it needs to be. Do I remove the TC and mount it to the trans then install the motor, trans, and TC as one unit? I was thinking I would leave the TC in place then install just the motor and trans. I am doing this all with the body on the truck.

I am hoping the stock oil pan will fit since the truck has a little lift to it. I will keep looking. I think it was just reading so many posts of dirt cheap 5.3s with low miles. But those were all much older posts I realize now.

I guess that brings up another questions. Does it matter if the donor is 2wd, 4wd, or AWD. Found an 02 2wd escalade with ~150k. LQ9 mated to a 4l60e.

[chakah]

I am currently swaping on a '63. Just like any other project, the spending builds up. My project is a LY5 Vortec off a '08 Tahoe (Gen IV). Keep in in mind, I believe '07 and up came with AFM. (Active Fuel Management), where you cylinders work from 8 to 4. Look up on LT1swap.com and it explains everything upon it, plus more. Tons of info on that site. On the harness part, if you can get a complete deal including harness and ECU would be better. You'll save lots of $ doing your own harness. Plus, I'm not sure if the aftermarket harnesses include the tranny wiring. I was shaky myself also, but I've accomplished a lot learning on that site. Do LOTS of research. It pays off at the end. On the subject on AFM, I did my own delete. Swaped the cam and lifters myself. There is also lots of info on Youtube. There is videos from UCanDoIt2 and he also very helpful. I plan to post pics later on this site after it's done,...damn camera takes lots of your time....good luck

[mongocanfly]

I'd keel the transfer case separate and mock it up to the trans on the floor..that way there are no surprises while your laying under a truck...if I remember right you'll need a 2wd trans for the AA kit..I'd set the engine and trans then put the transfer case on...that's way to much weight and length to balance it out while installing if it's all connected...it can be done ...just not easily...
Be sure to set your driveline angles correctly...
Snowballs grow quickly...haha

[C.I.Blazer]

Thanks to both of you for the advice. I have been doing A LOT of research which has really been a lot of fun. I spoke with Advance Adapters and it looks like their kit works with either the 2wd or the 4wd 4L60E. Hoping to stick with a gen III engine if I can find one with decent miles on it for a decent price.

I think I am getting a handle on what is needed for Step 1. So, now a Step 2 question. I have what appears to be a Northwest Metal Products after market fuel tank. This is the large tank (~38 gallons) with the bolts that go through the tank and hang from the bed of the truck.

I understand I my options are to go with either an in-tank or external in-line pump. Sounds like the in-tank are more reliable but I have to say that I know of a lot of issues with the in-tank pump on my 2004 suburban. Swapping them out involves dropping the tank which is a PITA. Sometimes, I wish I had a frame mounted pump to make the swap easier or need to cut a hatch in the floor to access the tank from above.

Anyway, one option would be to swap in a Boyd's tank (which has some $$ associated with it), but what are my options for keeping my current tank. I know I need a return line attached to it for an in-line pump, but how does one do this? Can I add an in-tank pump to the NWMP tank?

As always, thanks for the help.

[Captainfab]

Yes you can add an in tank pump to your existing gas tank. It will require cutting a hole in the top large enough for the pump and it's hanger and installing either some rivnuts or an internal threaded plate so you can bolt the pump hanger to the tank and have it sealed. No matter what method is used to perform the work, it is quite risky on a tank that has had gas in it. There are precautions to take to help prevent an explosion.

[C.I.Blazer]

Thanks Captainfab! Do I need to worry about the fact that there is not a sump in the tank? I would hate to add one because the tank is so large and already hangs down pretty low.

[C.I.Blazer]

Well, looks like I am committed now. Found a deal on a motor and transmission that I could not pass up. It is an LQ4 with a 4l65e out of a 2004 Yukon Denali. Truck had 132,000 before an accident. Came with all the accessories plus a whole bunch of staff I will probably never use (I did read somewhere to get as much as I could just in case). I got everything mounted to the motor plus complete harness, pedal, TAC, air filter box and connections, radiator and hoses, shroud, exhaust pipes including O2 sensors and cats, fuse box, and probably some other items.

[Captainfab]

No you really don't need a sump. However most in tank pump assemblies have a tray built in to help keep fuel around the pump pickup screen. I would suggest checking around to see if someone offers the '69-'72 Blazer tank already modified for EFI.

Originally Posted by C.I.Blazer

Thanks Captainfab! Do I need to worry about the fact that there is not a sump in the tank? I would hate to add one because the tank is so large and already hangs down pretty low.