rockin86ranger

I have a 1990 silverado I got with a bad 350 and recently got a 5.3 for it, I have been doing research and just want some clearification on couple of things.

I am still undecided on a transmission I have a 700r4 and while not my first choice it is there and works great, I heard mention that you can use the space and flex plate from a truck with a 4l80e to make it work with a 700r4 ( eventually a 4l80e upgrade is in the plans). I am not worried about the tv cable I can work that out on my own but what flexplate will I need and what starter will I need to use.

My other question is what is a good oem option for a fuel pump in this truck, I will probably end up upgrading the fuel pump later (if I get the rest of the parts gathered) but would like a cheap junkyard option to make sure everything is lined out and so I can drive it until summer.

I know most of this is covered in other areas but I haven't found anything that makes me confident in the information so hopefully somebody that has been there and done this will be able to give me a straight answer.

droopyzda1

I just did a 5.3 swap in my 1994 c1500. I used ls1truck.com and they gave me alot of info. Use the 5.3 flexplate. Bolt that to the crank and then the spacer over it along with the extended bolts. Must use the 5.3 starter. Spent the money on ebay like I did and by the ac delco fuel pump off a 1996 and newer c1500. Its like $60 shipped. I took the bed off to change it. I did not want to go again later if I were to put on a used pump. It was also easier since I had the bed off to install lowering shackles and hangers. I made my swap a headache cause I bought the truck not running and the owner assured me 4L60e trans was fine and after the swap was done, and I went for a test run, the tranny's 3rd and 4th clutches were bad. If u want to install a 4L60e, make sure its a 96 and later, they hold more power. I just got a 2003 and am going to install it in the next few weeks when i have time. 93-95 have 12 pin connector and do not have pwm which is suppose to soften the shifts.

rockin86ranger

Thank you very much that is 100% exactly what I expected to hear but I wanted know for sure before I spent the cash on everything.

rockin86ranger

I heard mention of the holes having to be slotted a little on some of threads I read, but I don't remember what exactly everything came from. Will the 5.3 flexplate bolt to the 700r4 torque converter, I know 4l60e and 700r4 are essentially the same but that doesn't mean they use the same pattern.

rockin86ranger

So I got most of my harness labeled but there are three plus I haven't been able to figure out yet (might have something to do with it being 2am)

The harness came from a July of 2003 avalanche 4wd 5.3

The first one is two plugs one for two pins and one for four that only has three slots used. The two slot on has wires that are green and yellow, and the other is pink or red.
The three wire one is blue, purple, grey?
They are split off the main harness along with the plug for injector #1, I found some that had 4 plugs on it instead of two which is why I am confused. (I would have labeled it when I pulled it but it was already removed which I really can't complain about).

The next plug comes down the main harness and splits off on it own at the same point some o2 sensor split off along with the mfa plug and low coolant sensor.
The mystery plug has three slots with wire colors grey, light green, and orange with blue or black stripe.

rockin86ranger

The picture in the last post is the second plug, this is the first one. It won't let me add more than one pic to a post

Fastoys

Not an expert but it looks like the gray, Lt green, orange/black should be for the MAP sensor, if that's the case they should go to pin 32 (Lt green), pin 54 (orange/black) and pin 48 (gray) on your C2 connector (Red at PCM), no luck on the other one.
Hope it helps, Rob

rockin86ranger

Any help on the mystery plugs I have everything on the harness done except my fuse box modifications and these plugs (already removed everything else I knew I could)

droopyzda1

Sorry, but I must've fried my brain going over the harness mod. I plugged the harness to each sensor, coil, injector and what not when I had my engine on the stand then labeled each one. As far as the flex plate is concerned, yes you have to enlongate the holes and make them oval shaped to get the 700r4 torque converter to bolt on to it

rockin86ranger

Wish I had that luxury, that's how I wanted to do mine but I do not have the engine with me it is 60miles away at the other house. I used all the information I could find online and went from there but somehow that plug got left out.

ls1nova71

iTrader: (4)

In bold print

rockin86ranger

Thank you very much

rockin86ranger

On the c1 connector I have one wire I am cautious about deleting, the number 59 slot a yellow wire is labeled serial data 2. I found a site that said this can be deleted but what exactly does it do and how will affect my ability to wire in an obd2 port.

Another question the same site showed that he used a four block fuse block I think I am going to end up with a 5 slotted block, would it be better to use one slot for all 8 injectors like they showed and use the other slot for something else or split the injectors into 2 slots. Just seemed odd to me to take 8 wires and bring them down to one slot, I know they don't pull that much though.

I am not new to doing stuff like like this but there's more than one way to skin a cat and I want to do it the better way.

ls1nova71

iTrader: (4)

There are 2 serial data lines, but you only need the #58 dark green one that goes to the ALDL connector under the dash, the other one goes to the body control module. As far as fuses go, I personally separate them into 2 banks, that way if there is a problem down the road and you get a short or something, the engine will still kind of run on one bank. If they're all tied together and you have a problem on one side, you're just dead in the water, Also helps on tracing a problem, you will know which side it's on rather than just knowing it's in the whole harness somewhere. I usually end up with 2 of those blocks with a total of 8 fuses, but that's just my preference.

rockin86ranger

That's kind of what I was thinking seemed odd to in a sense put all your eggs in one basket.

ls1nova71

iTrader: (4)

Haha! Yeah, that's a pretty good way word it

llorracs93s10

iTrader: (5)

I did not have to elongate holes for my 700r4 to bolt on my 2003 5.3 . I used the spacer and trans bolted right up. I do have a TV cable for the 700r4 to 5.3 vortec if you are interested? you will just need to make a bracket to hold it to the TB and should be good to go.

I went with a walbro 255 pump and new sending unit just because I didn't want to have to drop the tank again if the sending unit went after putting new pump in.

rockin86ranger

Right now I have a lead on a 4l80e for $100, no reverse but all forward gears are good. If it's still available when I get paid I am going to get it and use it for a little bit with no reverse to get the kinks worked out then pull it and rebuild it. No need to rebuild it and find out I needed the money elsewhere. I will rebuild it myself $200 for the kit and then fluid ~$50, $350 for a fresh 4l80e is fine in my book (hopefully won't need hard parts, and going to check the torque converter). Might use the 700r4 if the deal falls through but it won't handle the power later and I hate double buying parts

rockin86ranger

Well my 4l80e deal fell through. What do I need to look for when looking for another, I heard 95 was an odd year but that's the only one I heard. I found a 92 trans for a decent price would it work. Also does big block or diesel make difference (besides toque counters)?

rockin86ranger

So it didn't take long for this project to get pushed to the bottom of the list, while at a local car show I found a replica of the Boyd Hauler (build for Eddie Van Halen) with an ls1 in it. The original was one of the trucks that made start to appreciate these trucks and after seeing the ls in it I realized it was time to pick up on this project again while I am no longer working and have some free time.

Right now I have a couple of quick questions
1. When wiring in my fuse box where do I need to source my power for the tire fuse lock from? I know I had all of this figured out while I was working on the harness but not I just got my self lost and want confirmation so I don't screw something up while making a decision while my brain is foggy from so much wiring.
2. While talking to my dad at his work today I noticed a set of ls heads on the floor and found the owner to be one of dad's coworkers they are 706 heads and while I have a set of head on my motor I might be able to swap so stuff I don't really need for them if I Can use them. I have not done any port/polish work before and really have been wanting to give it a try. I found something that mentioned some 706 having a bad casting what should I look for there. Secondly what is the reasonable power limit on a set of ported 706 heads right now I am just planning on a cam the heads and some headers but eventually I would like to go with turbos but that might be a ways down the road.


Hoping to make some progress on this shortly (going to try to get the truck and motor to my new house this weekend to start working on it)