RONIN LSX

iTrader: (43)

My trans in my 96 GMC 1500 2wd (4l60e), work truck, is slipping bad. When I test drove it, it seemed fine, but as soon as I hooked my 2000+ lbs trailer to it, is when it started acting up. It started to serge and kick and now it won't go into 3 gear. I was told I probably lost 3/4. Well a buddy of mine has a 4l80e (not sure of the year) and he's going to give it to me for $300. Will a L80e fit into the 1500, without any issues?

Thanks guys!!!

1bad2k

iTrader: (11)

Yeah it will bolt in, but you'll need to modify your crossmember, cooler lines, 80e flexplate and spacer then decide how you want to do the conversion tune portuon. They'll also need to adjust shift points and all that. Many have done it and there are a few threads that give great detail. It's was more involved than removing the 60 and bolting in the 80 though.

RONIN LSX

iTrader: (43)

WOW! It's easier to bolt the damn thing in my 01 Trans Am, than a truck... who would of figured, lol... Thanks Bro!

Fast355

The trucks easier to make it fit. The GMT400s had a C shaped open frame. Slide the crossmember back, drill 4 holes if they aren't already there and done. Get the drive shaft cut down, conversion U-joint with the right yoke and done. As for the tune portion, I would 0411 swap that truck and use a 2002 1-ton 5.7/4L80E van tune. Put a 4.10 gear in the back of that truck and it will tow really well.

RONIN LSX

iTrader: (43)

Will I need a new engine and trans harness for the 0411? Where would I get the 2002 1-ton van tune?

BTW.... did this truck (96 GMC 1500 2wd auto) come with a 305 or 350?


Thanks guys!!!

Fast355

No just need to repin your harness at the PCM end to the newer 0411 connectors. Look up Lextech on the internet and he sales PCMs flashed with a startup tune and PCM connectors and has spreadsherts for the various wiring setups for various year trucks.

96 C1500 could have either. In the 8th digit of the VIN you will have a "M" for a 305 or a "R" for a 350.That is if it has the stock engine. It is not unheard of for people to swap one in place of the other either.

RONIN LSX

iTrader: (43)

What about the SpeedO, Mileage meter and ect... Will they still work? i read on here somewhere that a Frost harness was needed or something like that.

Thanks again for the help, Bro!

Fast355

That stuff will work fine after the swap. With the wiring diagrams and a little electrical expertise along with a junkyard 4L80E pigtail it took me all of 30 minutes to extend the harness and rewire for the 4L80E and additional input speed sensor. The 80E uses an 11 wire connector and the 60E a 13 wire, giving you the two extra wires needed for the input speed sensor.