Author Topic: 87 4x4 6.0/6l90 swap  (Read 4537 times)

Offline ehjorten

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Re: 87 4x4 6.0/6l90 swap
« Reply #45 on: October 19, 2018, 04:35:14 PM »
That I don't know, sorry!
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline jobobcat18

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Re: 87 4x4 6.0/6l90 swap
« Reply #46 on: October 20, 2018, 05:53:01 PM »
All good. Thanks bud

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Offline Captkaos

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Re: 87 4x4 6.0/6l90 swap
« Reply #47 on: October 21, 2018, 12:27:24 PM »
how would it be to run a 10 gauge wire from the battery or alternator (which was recommended by tre and racetronix) and choke it down to a 14 gauge wire going into the bulkhead
I used Racetronix Sy/Ty Hotwire kit and told them the connectors to match my R10 so it just plugged in.  On the Fuel sending side I paired the main wire to the 2 bulk wires running to the pump.  Been this way since March of 2014.

This is a link to my truck Racetronix post:
http://forum.73-87chevytrucks.com/smforum/index.php?topic=12120.msg230762#msg230762

This is the pump with the 2 14g wires merged

Offline jobobcat18

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Re: 87 4x4 6.0/6l90 swap
« Reply #48 on: October 21, 2018, 12:31:35 PM »
how would it be to run a 10 gauge wire from the battery or alternator (which was recommended by tre and racetronix) and choke it down to a 14 gauge wire going into the bulkhead
I used Racetronix Sy/Ty Hotwire kit and told them the connectors to match my R10 so it just plugged in.  On the Fuel sending side I paired the main wire to the 2 bulk wires running to the pump.  Been this way since March of 2014.

This is a link to my truck Racetronix post:
http://forum.73-87chevytrucks.com/smforum/index.php?topic=12120.msg230762#msg230762

This is the pump with the 2 14g wires merged

Thanks bud! I ended up just modifying my sending unit and ran a straight through wire sealer thing with 12 gauge wire. 26 bucks for the unit. We made our own harness and such.

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Offline jobobcat18

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Re: 87 4x4 6.0/6l90 swap
« Reply #49 on: November 08, 2018, 09:32:13 PM »
So I my fuel pumps will be wired to the back of my alternator. The factory fuse box (from the van) and the electric fans will be wired to my battery. And ideas on how to add more connections to a side post battery?

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Offline jobobcat18

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Re: 87 4x4 6.0/6l90 swap
« Reply #50 on: November 10, 2018, 04:11:02 PM »
What are yall running for a cold air intake on out trucks with the ls?

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Offline jobobcat18

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Re: 87 4x4 6.0/6l90 swap
« Reply #51 on: May 18, 2019, 04:41:10 PM »
Just wrapped up my swap and some key things I learned.

1. If your donor engine comes with an e78 ecm (which is found with l96 6.0's and 6l90e transmissions) do not use it. Even though it comes with it and everything. Trash it and get an e38 and repin it with a gen 5 camaro maf sensor or one similar. I used the e78 and there are more headaches associated with that ecm it's unreal. Especially if you decide to cam it like I did.

2. Treperformance fuel pumps are garbage. Ordered 2 of them. 1 didnt even work when I got it and the other went out after 6 months at the tuning shop which required for me to have to buy another one and pay them to install it. I'm now using a deustchwerks (I think that's how it's spelled) 300 fuel pump which flows more than any 340 fuel pump I've seen and pulls 15 amps or less!

3. If you're running a 2wd 6l90 and want to mate it up to a np208 transfer case you will need to pull out the output shaft from the transmission and get a 32 spline input shaft for the np208. (32 spline allows for alot more meat on the output shaft compared to the 27 spline (I think its 27)). Then send off the output shaft and input shaft to moser engineering and have the output shaft cut down and resplined. I dont remember the part number but there are adapters that mate the np208 to the 6l90e that are less than 100 bucks. They're factory pieces. I think they're similar to a turbo 400 adapter to a transfer case. Youll also need to plug the two holes found on the back of the transmission case. I used pipe fitting plugs (or something like that) and put them in it. Then just put the shafts in and you're done with a functional 6l90.

4. Dont cheap out on stuff. I mean take a deal when you can but dont do what I did and cheap out on a crappy fuel pump and have to pay for it later.

5. Instead of buying say a be cool radiator or one of those high dollar radiators. Find a local shop that builds them. I got a high quality aluminum double pass radiator with two 12 inch fans and shroud for 425 from the shop. A way better deal.

6. The mpg will go up more than likely. I went from a tbi 350 and 700r4 getting 12-13 mpg on the interstate. To a cammed 6.0 (about 520 horsepower at the crank) and 6l90 and got 17-18 mpg on the interstate. The truck has a 3" lift and 33x12.5 mud tires and is an 87 4x4. That number may sound hard to believe but it was hand calculated and I couldnt believe it myself until I seen it. I thought something was messed up with my gas gauge at first until I filled it back up.

7. If it's your first swap. You're going to learn an absolute ton! And its oh so worth it when it's done.

If anyone has any questions I'll do my best to help out!

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« Last Edit: May 18, 2019, 04:49:19 PM by jobobcat18 »

Offline jobobcat18

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Re: 87 4x4 6.0/6l90 swap
« Reply #52 on: July 22, 2019, 05:13:58 PM »
So the truck started overheating when it was in the middle of the day hot outside in traffic. The big aluminum double pass radiator and 160 degree thermostat couldn't keep it cool. So I decided to look at the fans. They both worked but they were only 11" fans that came with the radiator from the local guy. Swapped those out for 2 12" extreme performance spal fans (rated at 1870 cfm) and all I can say is for 12" fans, you're going to be hard pressed to find any that flow more. The attached picture shows the size difference between the two.

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