Hi all. can someone give me a clear definition between the 4L70E, 4L75E, and the 4L80E? And are they all the same Bell Housing bolt pattern? This will be going behind a mildly built '71 455". I have a conversion plate to bolt up the 4L70E. Will that work w/the others? Many thanks. wfg4u@aol.com. /or here!

 

Sorry all. in my last post i meant the 4L60E. Thanks.

 

These are all derivatives of the 700R4; each subsequent one is beefed from the last. All came with the Chevy bolt pattern. Some versions came with the 60 degree metric pattern as used on the V6 families. The later versions have a bolt-on bellhousing, but no one yet makes a BOP bellhousing that I'm aware of.

 

Even the beefed up factory versions died often. My 4L60E got the dreaded weak reverse. Our 03 shop truck burnt up the 3/4 clutch pack. It was so common, the trans shop asked for the vin. Because it was the right year, a replacement trans from GM could be bought for cheaper than a rebuilt. Als came with a 3 year 160,000 KM warranty. Remember this was the so called better 4L65E. Go 4L80E, all need an adapter and the 4L80E is based off the TH400.

 

Thanks guys for the info. You've convinced me to go w/the 4L80E! But they r costly. When were they introduced and in what vehicles, is it possible to pick a decent one up in a salvage yard w/computer, or am i better off just buying a new one from? GM? Again, many thanks!!!!

 

1991 was the first year, look in 3/4 ton trucks and vans.