tuske427

iTrader: (1)

HI:

One of my projects I have going is installing an LS1 with an auto trans in an old Hot rod. The transmission shop sold me a 4l60e, but, the torque converter won't bolt up to my flex plate.

I've since heard the LS1 requires a 4l65e..

1- is there any way to successfully use the 4l60e trans with the LS1? (certain torque converter to purchase, modify the flex plate, etc?)

fortunately my needs are essentially stock. Looking for long term reliability.

2- will the wiring work between the 4l60e and 4l65e? I have purchased a painless wiring kit for engine management.

any suggestions or advice?

Thanks,

-BV

joecar

You need the LS1 flexplate which is different than the SBC flexplate.
With this, any 4L60E, 4L65E, 4L80E, 4L85E should bold onto LS1/LS6.

The 4L65E is a GM beefed up 4L60E and is otherwise identical.

8a8mfh

iTrader: (3)

You need a '98 LS1 flexplate and a torque converter spacer from a 6.0.
Bolting a non LS1 4L60E up to an LS1 is just like bolting up a th350, th400, 4L60, etc.

tuske427

iTrader: (1)

Awesome, thank you both for your help!

As you can see, my current LS1 flex plate and 4l60e trans do not align. (one bolt is installed, the others are now way off, as is the whole plate offset)

Thanks for your help!

-BV

12secSS

iTrader: (30)

Looks like you are using a converter with an SBC bolt pattern (10.75") on an LS1 flexplate (280mm (11.02")). You need to find a converter that works on non-LS1 4L60E, but with mounting lugs for an LS1 flexplate. Or just find an LS1 4L60E.

8a8mfh

iTrader: (3)

I've never done this but read it here a 100 times.
Yes you have a newer flexplate like on my 2002, it's not flat. I have a spare '98 engine and it's flexplate is flat. Plus you need the spacer.
PLUS I'm not sure on the LS1 torque converter bolt circle but there seems to be only one size. On the older sbc torque converters there was a small bolt pattern and large bolt pattern and going by the picture you have the small bolt pattern which won't work. (as noted in the post above).

So it looks like you need a '98 (and I think '99) flexplate, the spacer, and a tc with a larger bolt pattern.

You could get a specially made tc for an older 4L60E to bolt up to an LS1 but I think it would be cheaper to get the other parts.

Or one other option, if you live in florida and your engine controller will work a '98 4L60E I have one I'll sell you cheap, it came from an LS1 with 113,000 miles, it ran.
But thats only delivery/pickup.

tuske427

iTrader: (1)

thank you all for your help!

TCI has a flex plate for the ls1 with a dual pattern set up. (one for ls1, one for sbc) hopefully this will work. Guess I'll need a spacer also.

Or, if I can find a torque converter to match up?