MustangEater82

iTrader: (1)

So I have had a 1985 z28 5-speed t-top car. Engine let go, car has been sitting for about 2 yrs (had a kid been cleaning up under the hood to be as good as the rest of the car) my original plan was a crate motor, t56 and probably a aftermarket fuel injection.

I have had some 4th gens in the past, I had looked into an ls1 swap, but it was looking pricey to piece everything together. But I found a deal on a totaled heads/cam 2000 z28, so on a whim... I jumped on it figure since I was looking for a bunch of 4th gen stuff anyways, might as well get it at once. I still have some prep work in my engine bay and need to get deeper in the details. I am going to start with the guides here. You guys know of any others guides elsewhere? Kind of a whim buying it so hopefully no regrets!


The third gen.




The gimpy catfish...
The good side...


The bad side

mwfrels

Very nice looking '85 you have there! The stickies at the top of this forum are the best collection of info for an LS swap that I know of. Also your donor car looks like a good source of extras to sell off and recoup expenses when finished.

A month or so ago I found a good read in GM Gen III LS-Series Powertrain Control Systems by Mike Noonan. I wish I had found it earlier.

Good luck on your swap.

M

WTR388

The stickies here and some other odd threads also found on here are really all you need... Honestly, it's fairly simple, and the wiring isn't that bad in the end. Having a 4th gen car you're practically half way done lol. Harness, fuse block (or you can do a nicer set up), the tank with pump, all the accessories etc... It's the way to do it. If I do it again, I'm going the same route (but, hopefully my next LS engine is a 6.0 with a supercharger).

86White_T/A305

Best advice..take your time,and use everything possible from the donor including the brakes,seats console ..rearend etc and you will have a nice 3rdgen in the end.Its not a hard swap by anymeans.No harder than pulling out and engine and trans..a few different mounts and stuff it back in.Wiring is tideous depending on how clean of an install you want.I did my last swap in 3 days from 305carb friday night to my lq4/t56 out the door monday morning.but its not my first rodeo. My first ls1 swap i did in a week taking my time making sure everything was right.I learned everything right from the stickies and picked pockets brain a few times about the wiring diagrams.the rest was just tuning minor details. Good luck with your swap..its worth it.

MustangEater82

iTrader: (1)

I wasn't too keen on the swap until I got a donor car. Couple details I need to look into...

Pedals assembly/clutch/throttle cable. Can I transfer over or do I need to mix/match pieces across the years.

Brakes... I am considering booster/master/etc.... I have an idea of what to do with the brakes on the wheels. The rest I need to fill in some blanks. I want newer then my 3rd Gen line. I might be ok using the lines off the ls1 car, or even ordering a new set. I am not completely against using an abs setup from the 4th gen has anyone ever attempted to swap it over? Or is there an aftermarket setup people prefer?

Interior parts, I have some research to do. Along with aftermarket guages.

86White_T/A305

If your is autot then use the 4thgen pedals and slightly bend the gas pedal away from the firewall to fully actuate the cable,some have used the 4thgen throttle cable aswell or lokar cable and make some sort of cap on the firewall.I modified my stock tpi cable grommet and used a lokar cable to have a cleaner look.Clutch etc is direct swap over.You can swap just the brake rotors/pads/calipers and get adapters and modify the stock spindles and reuse the brake caliper lines.Brake booster/master is bolt in but some masters have different line fittings.Dont know about doing a whole abs system swap..you would need to make custom lines for that and transfer any ecm/modules to control in into the 3rdgen..more headache than its worth imo.

Interior..seats are direct bolt in front/rear/. Console is bolt in..dash is technically bolt in but wiring needs to be done and custom make things to fill in panel gaps near the pillars..same applies to door panels.

QwkTrip

iTrader: (22)

You need front wheel speed sensors to make ABS work. I think you can use S10 spindles with ABS and get the system to work. Never seen it done though.

Here is a link how I did throttle cable. Frankly, I'v never seen a better method. I didn't have to bend the pedal either.

https://www.thirdgen.org/forums/ltx-...ml#post5823889

86White_T/A305

How you did your throttle cable is how I did my lokar cable and didnt need to bend my pedal either. Some have mentioned if you use the entire 4th gen pedal assembly they needed to bend the gas pedal to takc up some of the slack.

I wasnt a fan of the 4thgen abs system and how it feels under hard braking to say its worth making functional on the 3rdgen..would be cool to see though and get results.

QwkTrip

iTrader: (22)

Scratch that. I was thinking about traction control. I'm not sure about ABS.

WTR388

https://www.thirdgen.org/forums/ltx-...-t56-swap.html

Post 27 shows in pretty good detail how I did my Lokar throttle cable...

Reading this makes me realize I should have grabbed the brake master/booster off the car at the scrap yard today when I took all of it's calipers/rotors/backing plates... All for $50 ($50 if you can carry it in your hands in one trip out of the yard, didn't need to hit the gym today once I was done lol)

MustangEater82

iTrader: (1)

The abs, goes off the same wheel speed sensors, I'll have to see if mine was in the pumpkin or at the wheels. Either way, I might wait until later.


I think my next major project is brakes. I have read about different fittings, different years. I wanted to replace my brakes lines, whatever I did with the brakes, I figure if I can get something that will work on a 4th gen, setup, but fit in the third gen. ABS might be too difficult. I will have to research it some.