73-79 ls1 conversion questions

[red310055]

Has anyone put in a 00-02 5.7 LS1 with a 4l60e in a 73-79 square? If so what motor mounts did you use? what did you have to modify? what did you use for fuel system and you have to change the trans cross member? Any advice will help or anything i might not have thought of.

[mattcrp1]

Check the LS build section. I am doing a 2002 4.8l in my 76 (look in my sig). I used Dirty DIngo Mounts and relocated my cross member.

[Alex41]

Where in MD are you located? I'm near DC and I'm just about finished with an LS2 /4L65e swap on my 81. We can meet up somewhere and I can show you what I did to make it fit.

[red310055]

Alex41,

I'm in the northern suburbs of DC. What motor mounts did you use? Did you go with a in tank fuel pump? Also is there a source in the DC area to get an LS?

[Alex41]

Awesome. I'm near Alexandria on the southern loop of DC.

I ended up using the stock GTO pedestal motor mounts and making my own set up on the frame.

I used a Walbro 255 in tank pump on an 87 sending unit with the corvette fuel filter.

As far as sourcing an LS motor up here...good luck. lol. I got STUPID lucky with mine and we pulled it out of a wrecked but running GTO with 69K on it. I got it with fans, radiator, wiring harness, some fuel lines, engine, and trans for 4K. I don't expect you can come across that every day but they are out there.

[Captkaos]

My whole swap is documented at the link below and includes removal of the 305/700R4 to the install of the 6.0L and the twin turbo setup.

http://forum.73-87chevytrucks.com/sm...topic=12120.60

I used plates with the existing motor mounts (you can get them for less the $60) You can use your crossmember, it just needs to be relocated back. As for fuel I would use an intank 87 sending unit with a EP381 or 241 pump mounted in it. This will go into the existing tank, just don't run the tank really low. This has been done A LOT. I tried to put as much detail as possible in my thread.

[red310055]

Thanks Captkaos for the information. Your build thread is a great source of information. That is one sweet truck you built.

[Captkaos]

Thanks red310055

[Wgesnerjr]

Hi there,
Long time reader, first post.
In the middle of my swap now in the father-daughter C10 project.

1985 Chevy C10 Custom Deluxe 2WD LWB. 95,400 miles. $200.00 Originally a 305 4bbl, 700R4 but they were long gone before I bought it.

2003 Tahoe 5.3 Flex Fuel, 4L60E, 170K miles $1400.00 Rewired stock harness myself using LT1swap.com instructions, reprogrammed PCM by LT1 swap, stock air cleaner, fan, intake, DBW pedal & box, fuel lines, coils, starter, battery cables, truck accessory drive, P/S pump, ALT, Water pump, etc.

Just last weekend tried the motor and trans for the first mock up and it fits better than it should being that they are 18 years and 1 bankruptcy apart. Can fit 1-2 fingers between engine and firewall. Trans clears hump nicely but close. Stock oil pan fits the frame like it was designed to be there.

I have gone with the cheapest stock clamshell motor mounts (made new in china, bought from autozone) and some LS brackets off of eBay from KDS-Perfomance out of Michigan, $98. They fit very, very well and the motor dropped right in.

The trans cross member had to be moved back but works well. Used stock 700R4 mount. (Cheapest, New, China, Autozone) Drive shaft fit without any modification. However, getting the exhaust over the crossmember might be an issue. Also, the shift linkage fits right up and works like a dream.

The truck exhaust manifolds fit on the driver's side but hit the motor mount plates on passenger side. Also the flange was VERY close to the frame on that same side. Could have notched the frame but thought that might not be a good idea. I have ordered some Camaro manifolds for a test fit but they are not here yet.

Planning on using the stock Tahoe fuel lines and fuel filter set up. Will have to modify them as they are too long. Bought a new 1987 sender and tank as mine was rusted out. I wanted the 87 because it has a pan in it for the pick up. Using a Delco EP381 pump in tank so it will be quiet, cool and goes right on the sender. Still looking for a 1987 truck side plug to wire into the engine harness so it will have power. Haven't even mocked this up yet, but soon.

Plan on using the stock 1985 radiator but have not completed a test fit yet. (entire front end is still off) Will have to modify the Tahoe trans lines to fit the radiator. Bought new Tahoe upper and lower Rad hoses that look like they will fit, but have not mocked them up yet. Also plan on using the 85 radiator heater hose nipple for the steam tube hook up. (if I can find an adapter to work) Oh yeah, need to try the original fan shroud and Tahoe fan for fitment.

Also tried the 98 A/C bracket mod but felt it was not strong enough as it mounted to the engine with one bolt and depends on many brackets to stay put. Will use the Holley one when I get to that point.

Since I am using the Tahoe's battery cables, (the 1985 ones are long gone) I moved the battery to the driver's side using a stock tray and bracket from the junk yard. Will use the passenger side tray as a holder for the stock Tahoe's air cleaner.

Also using the Tahoe's underhood fuse box since I had it and need some relays and such. Now trying to merge the 85 engine harness with the 03 engine harness. Also, switching to an 89 suburban cluster so I can have an electronic speedo.

Gas pedal is totally not in the right direction and will need A LOT of modification to get anywhere near the stock position.

This swap is not a drop in, but pretty close to it. I have a long way to go but it has been fun and everyone I tell gets really excited. My daughter has learned to solder wires, remove fuel tanks and lines, convert rust and send fenders, hang doors and lift beds off of frames. I really enjoy bonding with her. She has picked the new color, 2014 chevy truck midnight blue effect.

[greg64]

Looks like a great team project, Jay.