Just wondering if I were to install an LSx engine in a '66 Ninety Eight LS with an automatic transmission would I still need to cut the transmission tunnel like in a Cutlass?

I'm thinking my 425 is gonna bite the dust shortly. I've always been interested in doing this type of swap but not if I have to cut the body.

Also what LSx engine transmission combo would you recommend I look for?

 

You don't have to cut the transmission tunnel in a Cutlass with a modern OD 4L60e or 4L80e automatic.
The 4L60e is just a computer controlled 700R4.

Only have to cut the tunnel in a Cutlass with the Borg Warner T-56 6-speed, TR6060, or the 6L80e.
Even if you chose to go with the 6 speed, the cutting of the trans tunnel is just like cutting
out rusted floor boards and putting in new ones. It's not a big deal, unless you don't have
the tools or the cash to do it.

I'm cutting mine out today. Just did my EFI B-body tank yesterday.

This is a pretty vague question.

It's like asking what car you should buy, without telling anyone your budget or what you want it for.
Be more specific in your realistic budget and your goals. You on a Ferrari budget, or a Pinto budget.

I could just say buy the 638 Supercharged LS9 that's $25,000,
or buy a 275hp used 5.3L for $1000 complete out of the boneyard.

Building a drag car, a weekend warrior, a pro-touring car you want to drive more often.....etc etc.

 

Thanks for the info Ace.

Since its a 66 Ninety Eight i'm definately not going to be racing the beast!!! LOL Its just something to cruise around with and possibly drive it to work more frequently due to better fuel economy.

What do you mean you can't tell me what engine I need??? Did you forget your crystal ball today!!! Not very professional!

As far as the budget goes I would be comfortable spending betwen $1k-$2k. Would it be possible to get an engine tranny combo that would work for that price? Some of the reading I have done already sugests certain engines would require new oil pans & intakes.

 

$1,000 ....not a chance in hell.

$2000 will be close for a baseline 5.3L engine ONLY, but you've gotta know how to modify
the harness yourself, modify the computer ($500 for HP Tuners or $800 for EFI Live)
and do 100% of the install yourself to even come close to that goal.
If you don't have that kind of skill level.......don't kid yourself.

You really should add on a modern overdrive.....so you're not going to do it for $2000 IMO.
Double that is your safe range to be in. I personally tell people to go for the 5.7L or 6.0L
instead, you'll be happier with it. But that's just one man's perspective.

 

Not too worried about the skill required to install the unit. Have been a licensed mechanic for 15 years and now teach mechanics for an auto manufacturer.

Do you always go with modified factory ECM's or have you ever done an install with an aftermarket controller? I have built a number of high power turbo engines using systems like SDS(Simple Digital Systems) and Megasquirt.

I was thinking about running one of these types of systems since I like to program the fuel and ignition maps myself.

 

Seems like for that much money you could rebuild the 425 and make it reliable. It wouldn't help much with fuel economy, but you would still have the original engine in the car.

I may be in the minority here, but I don't worry too much about fuel economy in my classic cars. They just don't get the miles on them.

 

Mechanically inclined meaning you can read a modern automotive schematic and rewire the ECM and add a fuse panel and relay setup where needed ??

If that's the level you're at, you're good to go.
Not familiar with those systems.

I stick to the factory ECM's because they're easy to modify, cheap and easy to replace.
There's literally thousands out there in case you want to build one for cruising, and one for dragging.
You can pop one in and out in seconds , and they're so cheap to keep spares.
I'm not familiar with the costs associated, so it's one of those things where you gotta do a side by side comparison to see if it's worthwhile.

A modern ECM goes for $100 - $150.
You pay ~$150 to remove VATS, and a few other details.
OR you can buy your own HP Tuners or EFI Live if you have the skills to do the fuel mapping in your case.

I hear EFI Live is just so much better though.

 

You do have a valid point about how easy it is to replace the factory ECMs. Definately something to consider.

 

What's your current trans and rear end?
Do you want a modern OD trans?

 

i've got the original TH400 with the switch pitch but really don't like the way it drives. Everything on my car is 100% stock right now.

If i'm going to the trouble of installing a modern engine I would prefer a modern overdrive transmission.

 

The OD trans is no big deal, but the 4L60 has a 0.7 OD, so if you're running a 2.73 or 3.08, you'll probably need to get a higher gear.
The cars came with a TH400, so a 4L60 will fit without tunnel mods.
If you want a budget cruiser, like I did), a 5.3/4L60 combo will work. Get it with EVERYTHING, accessories, pedal, TAC, wirring, ecu, MAF,O2 sensors, etc.
You can rework your harness with help from LT1swap.com.
All gauges can be reused except mechanical speedo. There are trans tail swaps and Cable X to use your original speedo.
Fuel system will depend on your tank. Flat tanks (A body) require a sump of some kind. Deep tanks can be used with external pump.
Engine location, motor plates, frame mounts will depend on trans location. You might as well try to reuse the driveshaft.
If you have AC, you'll probably need to make a bracket for that massive A6 compressor. An LS bracket is available for the R4 compressor, or you could loose about 25 lbs and put in a Sanden.

 

Would the driveshaft fit? Is the yoke size and spline count the same?

 

Tough to say on the driveshaft, you'll have to measure or mock it up. You can probably get a good idea on LS1tech by looking at chevy/TH400 to 5.3 or 6.0/4L60 swaps.
Dont know about the yoke, but swapping the yoke/U joint is only about $100.

 

Don't confuse the non-electric 4L60 with the electronic controlled 4L60e.
Don't forget the "e" on the end. There is a difference.
http://en.wikipedia.org/wiki/GM_4L60-E_transmission

TH400 output shaft is 32 spline
4L60e output shaft is 27 spline'
So yes you have to swap the yoke and shorten it ~3 inches.
You will have to either get a new crossmember or flip it around. I'm not sure on A-body's.

http://www.chevyhiperformance.com/te...ech/index.html

 

So I have read a couple of threads about putting these things into Cutlasses on the websites provided by Aceshigh.

A few people have used LS engines with TH400 trannies and apparently they pretty much bolted right up to the engine and tranny mount locations. They also mentioned using Edelbrock mounts which I am guessing are just poly mounts.

 

Lots of TH400/350 and 700R4s connected to LS motors. You just need the chevy bell housing bolt pattern, maybe a spacer between the flexplate and crank (depend on 4L60 vs 4L80 flexplate), and the flexplate bolt holes opened up.
Nice thing about the th400 is that it uses the electric kickdown that can be adapted to dbw engine pedals.
As for motor mounts, the 1" setback adapter plates will move the trans forward about 1/4" relative to the chevy mounting position. My 72 cutlass already had holes in the crossmember for both chevy and Olds frame mounts, so I bought a set of chevelle frame mounts on ebay ($20). A set of short/wide poly mounts allowed the LS to bolt in.

 

That will depend on which oil pan you use too.

F-body pan gives the best ground clearance, but longer front to back.
CTS-V pan is slightly deeper and hangs lower, but it's better fitting front to rear.
You can't use the 1" set back mounts with the F-body pan as Gary informed me.
I didn't have to find out the hard way.

All of this plays a factor in where your engine mounts in the engine bay.
I'm currently going through this part as well as my fuel system.

Gary I did more looking into your Nylon fuel line suggestion and discovered you were dead on the money.
I guess that link you posted on LS1tech wasn't showing me how cheap they were.
$2 per fitting VS $15 per Russell or Earls AN is a no brainer.
I went all nylon and bought the Dorman 800-300 kit.

 

Aces, be sure to post pics of the fuel system install.
Still kicking myself for not going that route.

 

Yes please post pics.

 

I'm waiting on my fuel sending unit hold down ring to get here from Florida. I ordered it from an Impala SS forum parts guy who likes to visit the yards. He also sent me the fill tubes. I'm just waiting on those and I'll be getting the fuel system complete HOPEFULLY by this weekend. I'll be posting pics in my thread.

Dude, it's going to be OH SO NICE to be able to shove flexible Nylon tubing through the frame rails instead of NON-flexible hard steel lines. I am sure I'll be done rather quickly with no cursing. I tried the tool out too, goes on like butter. I think I'm ripping my Camaro's rubber flexible braided stainless out and putting this in there too. I have everything already. I'll sell all those Russell fittings and come out ahead.