Change of Plans: Boy some of you purists have been unforgiving! After some soul searching and reflection, I’ve decided to pull the 403 and take it to a machine shop and rebuild it, even though it’s not the original engine. According to the research I’ve done, it apparently has big block heads (Casting number 389895-1 and a “B” on them) which makes them relatively rare maybe? Also has Edlebrock Performer RPM intake that appears to be ported appropriately for the 403 and flat top pistons, meaning it was built by someone for performance. Also has the Muncie M22 “Rock Crusher” transmission which is also a desirable system. When it was running, it had a lot of torque and would light up the tires easily. More to come…..

Thinking about installing an LS in my 1972 Oldsmobile Cutlass Convertible. I bought it knowing that it was originally a Cutlass Supreme Convertible made up to look like a 442. Also had the original engine replaced at some point with a 403 that appears to now have spun a bearing, so it’ll have to come out. My tentative plan is to upgrade the drive train and then tackle the paint and body. Looking for some input.

 

Do away with the gas all together and convert to an electric motor, but take the Oldsmobile emblems off of it.

 

recently finished an Ls swap in my 69 convertible- (many on this site will tell you that you should keep it all Oldsmobile). The swap was a big undertaking-( by no means am I a professional mechanic) lots of information about ls swaps on gm A-bodies. Combination of motor mounts, exaust, engine, will determine what will fit. I was not certain my hood was going to shut for the longest time- but it does.. i did mine on the cheap with a vortec truck motor. I was just thinking I should post some pics-

 

There's plenty of support available to LS swap classic cars. Use this website to find an LS motor in a salvage yard near you.

http://www.car-part.com/

 

Jam a Coyote or Gen 3 hemi in it. Be a man. Anybody can do an LS.

 

Could always go LT Gen V swap

 

Sounds like a fun project. The car looks great, why plans for paint and body work?

 

It really depends on what you are after...

For just a decent driver, it is hard to beat a simple 5.3 from the '99-2006 era - Decent power, decent mpg, reliable.

My winter daily driver in MN has a 2005 5.3 LS, my summer daily driver has a SBC. Both simple and reliable, but neither will get you in the purist club if that is a concern for you.

 

Do whatever you want. The chassis and suspension is the same as Chevelle (except the motor mount pads) so just research what the Chevelle guys do. Parts for a Chevelle are easier to find even if they're identical for an Olds.

Well, the Olds rear end usually has a 3R yoke while the Chevelles have, I think, a 1330.

 

Lots of information out there, but its scattered, some of it is out of date, and there are a hell of a lot of variables between engines, transmissions, accessories, and induction options. Here's a decent start:

https://ls1tech.com/forums/conversio...2-gm-body.html

It is a very expensive swap if you go the easy route and grab all the Holley parts. Its a very tedious process if you want to try to patch together junkyard parts and fab things up yourself, but you can save a ton of money.

 

It is your car, do what you want to it but don't expect too much support here. It is probably better than it used to be.

 

Some minor blemishes and areas of concern should probably be addressed.

 

We want to live vicariously through your project. You should forget an LS swap and find a Triton V10 for your Oldsmobile.

 

There are other cool engines to swap. I personally would rather sell my car than sbc or LS power it. Problem is mounts, pans and tunes for these oddball engines. The GM Atlas Inline 6, especially with boost and a tune, is very unique. Biggest problem is the oil pan, guys have combined the 4/5cyl pan with the factory pan. Don't go Gen 5, lifter issues and major crank failures on the last 5 years on the 6.2. My big issue with the LS, stock trucks at least, is they are worthless below 3500 rpm. Go 6L or 6.2L, unless boost is planned. Don't go 4.8 or 5.3, unless they are much cheaper. Unless you have a really good trans builder with a good warranty, skip the worthless 4L60E. The 2wd 6L van 4L80E transmission have factory 2000+ stall. Mine flashes at 2100. Most flash higher according to the internet. That could be the much different power band of the LS 6L vs my Olds 358. Get Chevelle swap parts and the Holley Terminator X Max has LS tunes out of box and controls multiple transmissions. Get a stand alone, all new wiring harness for EFI. One of my many EFI mistakes, actually had an under hood fire. I prefer these cars remain simple and primitive, like us cavemen who own and drive them.

 

Once again it depends on what the goals are. I have had real good luck with the 4.8/5.3 LS's, but you have to gear the car down to keep them spinning where they are happy - neither motor has much down low. A 6.0 is nice, but they suck the fuel down typically. The 6.2 - most who work on those motors for a living won't recommend that swap. I have also had real good luck with getting over 300,000 miles out of my 4l60e's, but it is no 4l80e - which is good and bad - for a driver, I prefer the 4l60e. The 4l80e is a brute, and feels like it while it does its job.

OP seems to have already figured out what path he is taking though...

 

A 4L60E with a STOCK 4.8 or 5.3 should be fine with a 4L60E in a car. The 4L65-70E is a slight upgrade with the 5 pinion planet gears. In a truck, 300,000 is something I have never seen. I worked on these trucks shortly after they were new. Many GM reman stickers, probably because these were farm trucks that towed. I blew the 3/4 clutch packs in our 2003 GMC work truck. It was maybe mid 200,000 Km, not miles. My 94 had I believe about 250,000 Km, according to my FIL. The fluid looked very full of clutches, my In Laws towed a small cattle trailer. I changed it, then had a super weak reverse. Yes the 4L80E is big and heavy. It just fits on my 70 S except the center cooling lines, need good dents in the floor. An Amazon 96 to 05 2WD Blazer rear driveshaft worked great with the factory Type O 8.5" 12 bolt, just needed to swap the front 27 spline yoke. It had a 1350 U joint up front, 32 spline yoke that came with the 4L80E went right on. The rear U joint was 1350 to 3R conversion joint.