My 1985 C-10 Silverado
 

Today I began my journey to swap a 5.3 LM7 into my 1985 Chevy Scottsdale pickup. I've been researching and reading a lot of forums over past couple months trying to learn as much as I can and trying to determine how I could acquire a good reliable engine and today I purchased my engine, which is a 5.3LM7 out of a 2002 chevy Tahoe with 160,000 miles and engine was still in car so I was able to listen to it run. Very clean engine and ran very smooth and air conditioner worked great! It has fan on it and it is a drive by cable. The harness, fuse box, PCM, radiator and cooling attachments will come with engine. He had already sold the transmission but it was a 4wd anyway so I'll either use my 700r4 that's currently in truck, attached to a 305, or find another 4l60E transmission. I'll be posting some pictures later.

Is there anything else on this donor car that I should try to get with engine? Also, any tips or suggestions that could in this project will be welcome.

Re: My 1985 C-10 Silverado
 

Sounds like a solid plan. I am not 100% sure, but I think it would be correct to get yourself the 4l60E that belongs behind your engine. I think it will simplify things. I am sure someone with more experience will chime in.

Welcome.

Re: My 1985 C-10 Silverado
 

The harness and fusebox are the two biggies, and you're getting them.

Daddyjeep is correct in that a 4L60 would be alot more straightforward to swap in and tune.

Re: My 1985 C-10 Silverado
 

I've read so many posts on various forums and looked at videos on youtube that I'm still not sure about what's the best way to do this type swap. Some of information I have is from years ago so I'm not sure if information I have is latest and best way to do this swap. I want to post some of information to see if it is correct. Any comments will be welcome!

I'll start with Motor Mounts. I would like to use the A/C compressor on the engine not have to buy the bracket to mount compressor up high and not really sure if there are motor mounts out there that will allow me to do this. Are there any mounts that will let me do this without notching the frame. Dirty Dingo, Holly, ECE, Tejas Steelworks, etc. Tejas Steelworks claims theirs will but on one of the videos I looked at, they had to notch out the mount and grind off a rib on engine behind motor mount so not sure if you can or not. I also saw a post that the 1999 to 2002 5.3 a/c system can be hooked up to your current a/c system in truck and that the compressor has a flat space on compressor that allows you to keep the a/c compressor without notching frame. Any suggestions here?

Fuel System - From all information I have, best option here is to buy the 1987 chevy TBI tank (only one fuel tank) with baffles and use the ACDelco EP-381 sending unit and use the corvette fuel filter/regulator WIX #33737 between fuel rails and sending unit. However, I read lately that some of the 5.3 engines from 1999 to 2002 may have two fuel rails and if they do then you don't need the filter/regulator and you only need a fuel filter between sending unit and fuel rails. Also not clear if the 1987 tank will fit in the 1985 truck without adapting the tank.

Enough for now.

Re: My 1985 C-10 Silverado
 

If you have a C10, the Dirty Dingo mounts will let you use the stock compressor in the stock location. You may have to grind the frame a little, I didn't when I used them, but some people say they do.

Re: My 1985 C-10 Silverado
 

The 1987 fuel tank is a direct fit..Using the in tank pump is a good idea. I had a inline pump and found the noise to be a bit annoying. You will have two lines all the way to the rail, so you will not need the Corvette regulator. I would get whatever fuel lines you could get off the donor. They will be bent properly to attach to the 4l60. Then use fuel injection rubber to the sending unit.

Re: My 1985 C-10 Silverado
 

Did your donor engine have mechanical fan or was it electrical? Mine has mechanical fan and I'm just wondering if I will have room for the mechanical fan if the mounts move the engine forward. I just read that if I change to electrical fans, it's not easy to get the current harness changed to accept the electric fans. Some say it can be done, some say it can't!

Re: My 1985 C-10 Silverado
 

Got the guy to sell me the fuel lines also and he has pulled everything and I'll pick up tomorrow.

Re: My 1985 C-10 Silverado
 

When sliding the engine forward to have room for the compressor I don't think there is enough room for a fan shroud. So electric is the way to go. There are plenty of donor vehicles to choose from. Mine came from a Escalade but there is pickups with them too. You can grab the relays and wiring also.
if you go over to the LSx forum there is a ton of information.

Re: My 1985 C-10 Silverado
 

the harness is easy to change over to electric fans. I have done quite a few of them. PM me if you need the harness updated. The PCM will need to be programmed to turn them on and off. Any good tuner can handle that issue. The PCM needs to be programmed anyway to remove VATS and a few other things. Depending on the speedo you choose to use, the programmer can adjust the gear ratio and tire diameter in the PCM and change the VSS output to match your speedo.

The Tejas Steelworks mounts are the simplest to use. I have seen a few done with his mounts that keep the AC compressor in the factory location of your engine.

The '87 tank and fuel sender with an EP-381 pump is the great solution. If your engine's fuel rails have two line, then you don't need the corvette filter/regulator.

I also like the PCM mount that Tejas sells. Clean way to install it.

Get a 4l60e to make your life simple. If you go with the 700r4, then the PCM will need more programming done to support that change without lighting up the check engine light with transmission codes.

Re: My 1985 C-10 Silverado
 

Picture of my 1985 Chevy Scottsdale C-10. Bought this truck about 10 years ago.

Re: My 1985 C-10 Silverado
 

Watching this closely because Im about to help a friend install one in his 86 Chevy Silverado.......

Re: My 1985 C-10 Silverado
 

I had a mechanical fan, I had to ditch it when I put the turbo on though. The Dirty Dingo mounts don't require moving the engine forward. The Tejas ones move it forward like 3"

Re: My 1985 C-10 Silverado
 

What radiator and electric fans did you use on your swap. I will probably get rid of mechanical fan and go with electric. I wanted to use my current radiator but not sure I can find electric fans that will fit.

Re: My 1985 C-10 Silverado
 

My swap will be slow going for a few months but we can keep up with each other. Looks like we are not far away from each other!

Re: My 1985 C-10 Silverado
 

I am using a stock HD radiator and a Mercury Villager fan.