CarsandWomen

iTrader: (19)

Looks like im probly swapping to the 80 in the near future so ive been doing my homework. Id much prefer to get a normal 4L80 converter and jsut buy a new SFI flexplate to match, that way i dont have the custom ls1-4l60/4l80e thing going on with the spacer and all that crap.

Currently im running the CAT Power FP and it was cheap and works great but ill be selling it with my current 4l60 setup.

so where can i find a stock replacement SFI flexplate for a 4l80?

98hc4mula

iTrader: (5)

what do you mean a normal 4l80e converter?
I ordered a flexplate from TCI with the wide bolt pattern so I can use a 4l80e converter Circle D spec it out for me. I think that is what you need.
Flexplate LS1 Engine to 4L80E Converter/Transmission Wide Pattern SFI Approved
PART #399754

slow67

iTrader: (2)

4L80E truck converter is different circle/depth from a stock LS1 car 4L60E. You gave the correct part number.

CarsandWomen

iTrader: (19)

slow67 is there anything you dont know about the 4l80 swap?

forcd ind

iTrader: (7)

i used the TCI on mine, you prob need the one with bolts and the spacer-the flywheel goes on then the spacer regis. to the crank and to the converter

slow67

iTrader: (2)

LMAO, I'm not sure. It also helps a good friend of mine is a great performance 4L80E builder

98hc4mula

iTrader: (5)

the spacer is so the converter is centrally located in the crank. it is an extension from the converter to the crank bc it will not reach. This is something I did not know to install so I had to drop the transmission one more time. It is now all buttoned up and waiting for the tranny tune.
good luck with your swap. make sure to measure and make it clear on the side of the harness and also on the rear cooler line.

CarsandWomen

iTrader: (19)

from now on im just gonna PM you all my Q's first and foremost, and on the slim-to-none chance that you dont know then ill post a thread, LOL. j/k

slow67

iTrader: (2)

Depends on the flexplate. The stock 4L80E flexplate is flat, so the GM spacer goes between the flexplate and the crank. Hughes has a spacer that goes on after the flexplate on a dished (4L60E) flexplate. Bad thing about that, is the converter bolt pattern is a little different between between 60E and 80E (it can work by wallowing out the hole a little bit, but I dont like that). I dont think the TCI 80E flexplate needs a spacer, I believe it is thicker, but I'm not 100% sure on that one.

98hc4mula

iTrader: (5)

its really not a spacer. It is actually an extension for the pilot of the converter. this is to ensure that it is centered in the crank.
The TCI flexplate does have thicker mounting points for the converter therefore no spacer is needed, it is becuase of this that the converter will be too far away from the crank to be in the pilot hole which is used to center the converter right on. if you dont use this piece, then the converter will only be secured by 3 bolts to the flexplate with any other contact to the crank, this may cause a mis alignment to occur and a wobboly problem can take out your balance and destroy your bearings and transmission.
at least this is what I understood from the research I came across. I am not too sure about the other flexplates, thanks for posting the differences from those and clarifying what was needed for each one.
I have learned a lot from you throughout this ordeal, I am glad that this board exist to help people like me who like to do their own work....
cheers

forcd ind

iTrader: (7)

i should prob call it a crank extender, lol

slow67

iTrader: (2)

Yeah thats all it does, center the torque converter snout.

Vetal

iTrader: (3)

Am I right thinking that if I buy this #399754 flex/bolts from TCI ( http://www.compperformancegroupstore...Category_Code= ), that is all I really need for LS1 + 4L80E converter?

CarsandWomen

iTrader: (19)

yes but that one is not SFI approved, the same flexplate that does have the SFI rating is the same price. Not sure if thats important to you or not but to answer your question directly, yes, that FP is all you need.

Vetal

iTrader: (3)

It says it's SFI approved. Yes it's important, I hope to get upto 1000HP, on slicks...

CarsandWomen

iTrader: (19)

oh my bad, mixed up the numbers, I was looking at 399753, youve got it right. I actually have 399754 in my garage, its pretty beefy. I wouldnt be scared to give it 1k at the wheels, I was able to compare it to my SFI 4l60e flexplate and its WAY thicker and heavier, built for power

Vetal

iTrader: (3)

Yes actually that's what I didn't like about it - the weight, more than 9lbs

CarsandWomen

iTrader: (19)

that just means it will hit harder and more consistent on the launch

Vetal

iTrader: (3)

Yes but not so fast on the street, when you hit the pedal...

CarsandWomen

iTrader: (19)

that was my thought too but after doing a lot of reading, most turbo guys preferred the heavier flexplate because it seems to help spool considerably. enough so that it overshadows the loss in whp. not my experience but its what i gather in general.