I own a '79 L-48 'vette and have found a complete LS-1/4L60E pullout from a '98 T/A for what I think is a reasonable price. While I have been a mechanic for most of my life, my problem is that I'm old school for the most part in terms of experience. Some of the things that I work on at my job use '46 Desoto flatheads, if that tells you anything. I know that there are other threads on this subject and, while helpful, haven't answered several questions that I have. What I'm looking for more than anything are sources. Does ANYONE make the adapter plates for this swap? Sources for converting the acc drive and which one works the best (I wish to keep everything functional), a book or manual for connecting the '98 electronics to my car, anyone's opinion of BTO's crossmember for a 700R4, and what years were the 4L60E made that were not 3 peice (3 peice won't work with BTO crossmember, or so I'm told). Any other info you guys could provide is very welcome. Thanks,

Bryan

 

I'm not sure about any books, but there are a few places that have wiring harnesses that will make the install alot easier. Speartech and Street & Performance sell them, but I found mine for $400 from a guy on Ebay where I got my motor/trans. S&P also has the tranny crossmember, motor mounts, etc., and so does BRP.

 

For the motor mount plates, S&P has some or you can use our plans that we have floating around and make them yourself out of 1/4" steel.
S&P's website is www.hotrodlane.cc
I have some pics of what I've done on my site www.kmmotorsports.com
I'm not sure, but I think that someone around here used the BTO crossmember and modified it to bolt in a T56. Maybe they'll chime in.

 

Thanks Guys, I really appreciate it. I ordered S&P's catalogue and will be checking w/ Speartech too. By the way Scooter, nice website, cool car. Hats off.

 

Don't know if it will help you much but if you wish to peruse my photo site at www.aei.ca/~nmaclennan and if you have any questions I'll do what I can to answer. The wiring, while time consuming, can make or break an installation.

I don't know how much room you have in front of the existing engine but if you have an inch, then you should have no trouble installing the 98 LS1/4L60E combo. (The removable bell-housing on the 95 and later 4L60Es adds a little over an inch to the length).

What's in the 'vette now for a tranny? Is it an option?

I used the Astro's stock 4L60E as it is a 1 piece case. I installed a Transgo kit and 'vette servo. The 98 PCM shifts the tranny beautifully. (read hard). 2 years plus running on my combo.

 

You must enjoy working in confined spaces. Holy Cow! I'll bet you surprise a few people though, that is awesome
I have a TH350 in it now. Shifts nice, but I doubt it would hold the power and live very long. From what i undestand, the 4L60E is about 3" longer than a th350. I can get a crossmember in, that's not too hard, my concern is the E-brake bracket not binding on the revised U-joint due to the shortened drive shaft. The pullout that I bought does have the three peice tranny, so BTO's wont work, though why they say that, I don't know, maybe because of the longer bell housing, but I don't see why I couldn't just move the cross back an inch..

 

I wouldn't worry to much about the 350 tranny as they can be made to stand up to damn near anything. I don't know much about the 'vette but I can tell you a couple of things I learned with my swap.

The LS1 engine doesn't have the 1"-1 1/2" extension on the block so the engine and tranny HAS to move ahead at least an 1". (If you look at the LS1 you will see that the block goes straight down from the R cyl head whereas on the regular cast iron SB there is about 1 1/2" before the tranny bolts up. This is hard to explain so I do hope you can follow my explaination.)

If you don't use the 4L60E tranny you will have to buy an adapter for the 350 in order to feed the PCM the VSS signal it needs.

Spend some time with the wiring diagrams of both vehicles and you will see what you can do away with in the PCM harness. There are quite a few circuits that can be done away with. I bought the under hood harness for an F-body car. It has 2 fuse/relay panels. I reworked the harness so that the circuits I needed were contained in one of the fuse/relay panels. This wiring harness then plugs into the engine harness and I only had to hook the van up to the fuse/relay panel to control the engine. The ignition switch controls a relay which is the same as the setup in an F-body. Makes it real easy and all of the LS1 circuits are the same as GM originally made them as far as fuses, relays, etc go. I personally feel the trouble was worth it.

Solder all connections and use heat shrink tubing on any and all electrical splices.

You may find that the AC compressor from an LS1 corvette may be what you need for your swap as the F-body compressor is bolted down low and may contact the frame.

It will take more time than you figure but if you don't rush things it will be worth it. I spent a little over 2 months on my swap. I usually worked between 4 and 12 hours on it. When my back got sore I quit. I also had to relocate the accessories and that required building new brackets from scratch. I used my router to fashion the brackets from a chunk of aluminum block.

If I was doing the swap, I would use the 4L60E and modify the hand brake linkage/cables as necessary.

You are correct about the surprise some people have when they figure they have that little 4.3 beaten before they get started. Priceless.

If I can help out let me know.

 

LS-1, you just saved me about 1 large. Many, many thanks. Using a router to fab brackets, now, why didn't I think of that? I had a side business building cabinetry and restoring antiques for years, so I have routers coming out of my ears (They're kinda like golf clubs). Do a mock up out of plywood, then use as a template. I take it that you used a spiral downcut bit or upcut? What did you do to prevent heat warpage? You are correct about the A/C not clearing. The stock vette setup might work just barely, but the A/C has to be mounted up high pass side or not at all. This will also help me with the dash, as I have plans to build something of a one-off dash, console and cluster out of aluminum patterned after the original, just more substancial and using more modern instrumentation. Once again, many thanks.

 

I bypassed the mockup out of plywood, etc and went directly to the aluminum. I used a straight edge on the crank pulley to get my base lines for measurements, held the accessory in place to get dimensions from base line(s).

Can't remember if my accessory mountings are visible on the web pictures, but I mounted the PS pump on the passenger side cylinder head(remote reservoir), the alternator on the drivers side (I used a 5.3 alternator bracket that I modified heavily) and the AC compressor was tucked in low on the driver's side. The AC and the PS were custom aluminum brackets. The AC being the most difficult to do as I used the AC compressor from the 4.3. I wasn't sure whether the F-body compressor would handle the front and rear evaps at the same time, I think it would based on what I have since found out and if I ever have a problem I will build an L-shaped bracket to mount the LS1 compressor. Don't forget to use BLUE Loctite on your mounting bolts.

I used an aluminum cutting tool in the router. Heat was not a problem as I couldn't make that much of a cut at any one time. Time consuming though.

Your dash idea sounds good and if you are doing that you might as well go with the 4L60E as you can get any of the new instrumentation to work with the stock sensors.

Any of the truck brackets (4.8, 5.3, 6.0) have to be modified because the truck engines have a different crank pulley (longer).

Send pictures of your progress or set up a web presence I can access.

Thanks.

 

LS-1,
I am using the 4L60E as I want the overdrive. Poor old shark is out of breath above 90 or so. Eckler's even carries a shifter conversion kit with an extra detent that makes it appear stock. Pretty cool.
Not only is the truck pulley different, but the T/A and vette pulleys are different from eack other as well.
I will be happy to post picks as the project progresses. It'll be a while though. Pullout is still in transit and once it gets here, engine and trans will be sent out for some work. About a month, I should think.
Once again, many thanks.