Aviator857

I am considering doing an LS1 swap into my 89 firebird. I understand the basics of mounting the setup in the car. K member, engine mounts, crossmember etc.

My car currently has a 700R4 tranny and I am really considering swaping to a manual trany, but would like to know if the LS1 will bolt up to a 700R4 or will I need to get a 4l60e(auto) or T-56 (manual). My 700R4 was rebuilt less than 20K miles ago with an upgraded valve body and shift kit. My current tranny will hold the HP, it may not last forever, but I would like to keep it until I am ready to tackle converting it to a manual.

Next question has anyone gotten the cruise control in their thirdgen to work after installing an LS1?

Can you use the LS1 air conditioner compressor with the rest of the thirdgen air condition parts, or do I need to swap out all the ac from a donor car? If I do the LS1 swap I will be getting a Spohn K-member so I can keep the ac compressor.

If I do a LS1 swap I want it to be 100% with all systems working no computer codes and I am planning on keeping most of the emission components in place.


If I don't do an LS1 swap I am either putting in a new 305 or 350. Is there a 350 engine that I can bolt all the 305 accessories and brackets to. Is there more I would need to do other than upgrade the injectors on a TBI to swap from a 305 to a 350?

StevenK

iTrader: (1)

I have not figured out the cruise control yet, I dont think anyone else has either.

Notch the stock k-member, cheaper, and IMHO the Spohn k-member is a peice of ****. And the one that Hawks sold before that (the one I got) is a even bigger peice of ****.

I'm using the 4th gen compressor with custom made lines to go to the stock thirdgen A/C parts.

Aviator857

What problems have you had with the K-member. I've heard that if the car has any frame warpage they are hard to get installed. I was mainly considering swaping out the K-Member to reduce the weight in the front of the car to bring the center of gravity back a little to help balance the car.

Do you know if the LS1 cruise control is vacumm based or is it controled by the computer?

ghettocruiser

iTrader: (4)

LS1 cruise is computer controlled with no vac. connections at all. The LS1 cruise is very simple to hook up, and you can mount the actual unit anywhere because of its shape and not needing a vac. line.

If you are ambitious enough, you can use 100% of the 4th gen a/c system. But its a lot of work. Otherwise, you can use the ls1 compressor with the rest of your stock a/c system.

In my opinion, if you are swapping the LS1 in now...just do the T56 swap now as well. The 700R4 might hold up...but dont forget, you are like tripling the power output from a stock thirdgen motor. It needs to be built pretty good to play well with the LS1. The best time to set up the clutch hydraulics and pedals is when the motor is out of the car and you have more room to work down on the firewall for mounting and positioning the master cylinder.

Another thing to consider... The thirdgen rear wont like the newly added power either. Most 10bolts dont, even the ones in the LS1 cars from the factory. So you might want to factor in some rear end ugprades into your budget project. Doesnt take much to grenade those 10bolts.

As for your quest to reduce front end weight... Just by installing the LS1 you are saving a good bit of weight. You are going from an iron block, iron headed slug to an ALL aluminum torque monster. You'll be ok as far as weight bias... A tubular k-member just isnt worth the trouble at this point if you ask me. Just modify your stocker for the a/c and be done with it. Every car is alittle different, and lots of people have been having issues getting the aftermarket k-members to fit properly. Some have great luck, some have no luck...

Do some more poking around, and ask any question you still come up with. Plenty of guys around that have done the swap by now that can help ya out. Seach is down over on ls1tech.com...but you can find all of your answers between this site and that site without even looking very long. There is a TON of info on thirdgen swaps on both these sites.


Justin

socal

look at 92z/ls2 in engine swap thats mine sphone kmember and toque are easy swap. We are still working on using the ls compressor on the stock system

Aviator857

I was planing on using the 4th gen rear. I will probably upgrade to a ford 9" at some point. My car has 2.73 gears in the rear anyways and the rear has 210K miles on it, for that matter my 305 does too. I am trying to do this swap on a 5k budget. I am looking at getting a donor ls1/tranny I am thinking around 3500 for that, 4th gen rear 200 ish. Parts to requild my AC in my car, and mounting hardware.

Is this realistic or should I wait unitl I have a bigger budget for the car? Once I get it running and all the wiring and subsystems working I will probably pull the car back apart to do a really good paint job on it in a couple of years.

So the bigest issue with the Tublar K memebers is fitting, are there any strength issues with them.

I am not building a race car, but a weekend cruiser that I can push really hard, and occasonally take it to the track.

Thanks for the info.

ghettocruiser

iTrader: (4)

Sounds like with your goals Ide still stay away from the aftermarket k-member...but thats just me.

$5000 is probably alittle optimistic. I have almost 10k in mine...and I bought my donor car for $6000... I made about 2500 of that back from selling parts.

General rule of thumb...whatever number you come up with, double it, and you'll be in the "safe" zone.

If you do just the motor and trans, and MAYBE swap the rear...you could probably do it for around $5000. But that number goes right out the window as soon as you have to do suspension mods or anything else not directly related to swapping in the motor. Also, if you run the 4th gen rear your 3rd gen wheels wont fit right anymore, and will stick out kinda far. Little things like that you run into...

Just be smart with your purchases, and try to plan out EVERYTHING you want to do to the car. Might be able to do it!

Justin

StevenK

iTrader: (1)

I had to completely redo my steering because of the crappy build of the kmember I got. Like I said, mine isnt the spohn one, its the one before spohn took over. From what they show in the pics, they notched the lower section of the k-member brace to help clear the tie rods, but I saw another thread saying another person was having the exact same problem as me. He ended up heating up and straightening the drag link, but IMHO that is not smart as it will create lots of bump steer, and toe-in problems.

I welded on a new idler arm, swapped out the idler and steering box arms to shorter units, so now my stock drag link clears, but I've lost a good 30% of my steering, aka takes 12309809 lanes to turn around.

socal

we did have a few clearance issues with the sterring as well but it was not that bad. we move the ideler arm around and ground down the a/c braket a little but we are running the a/c low in the stock location. 5 grand is a little optomistioc but do able. You can run the stock cast monifolds with the tubuler k member. We did the cro-moly on this car and i went with a mild steel one for my wifes car. shpon said there is only about a 5lb differance but the cro-moly in my knowlage is stronger, but the only thing thats cro-moly is the round tubuler parts look at 92z/ls2 i updated it w details

Aviator857

Thanks for the info. I may just drop a 305 back into it for now, or pull the one in it and rebuild it. It doesn't smoke but the seals are drying out and starting to seap, and the compression test on the cylindars are decent and consistant across them. I have headers for it in the atic but can't get the bolts out of the heads without breaking them. The valve covers have never been off the 305 in the 210k miles its been so many bolts are hard to get out. I should be able to do a 10k budget on the engine swap next summer, I don't want to cut corners. I have poly bushings the only suspension upgrades I want to do is to put adjustable panhard bar and drag links in it. I rebuilt the steering 30k ago its good although I need to pull out the steering gear and adjust it.

I've seen the 4th gen rear on a 3ed gen, and with the offset of the factory 16's on the rear it moves the tire out but not too bad.

socal

yes they stick out farther if you use the thired gen rims but its the same w 4th gen rims