LS2 4l65e dead.. rebuilt or go 4l80e?
- Thread starter Patobusta
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Stock stall depends on what you pull it from. I got my 4L80 from a 350 truck, so stalls a little north of 2000. My dually stalls around 1600. I 4L80 swapped my 1500 when the 4L60 took a dump on me. The taller gearing was very noticeable. . . with a stock converter. It's larger in diameter and a good 20-30# heavier than the 60's so has a significantly higher moment of inertia. If I had the same 2000 stall, but 2" smaller in diameter and 20-30# lighter the truck would rape. The gears are much closer together, so shift recovery kicks *ss with a stock stall. The overdrive isn't night and day, but did help keep the truck locked in OD with a trailer. All that and the peace of mind you get with the swap make it 100% worth it. My 1500 trans is a basic rebuild with Superior shift kit. It's been living behind a mild cammed supercharged 350 Vortec for the last 50k. Probably time for a filter or a flush now. The stock 4L80 in my dually, at around 150k, has been supercharged most of its life as well. Pretty sure I gave it its first flush this spring. I lived for 80k with a 3000# welding bed on its back occasionally pulling trailers. I've been nothing short of impressed with the 4L80.
I put an 4L80 In my 442. NO tunnel work is required and cooler lines are accessible. As noted you will need a saws all to cut the sides of the trans housing for header / exhaust clearance. My car has the factory 3.73 8.5 rear end and first gear is definitely not too long. I have major traction issues and wish gearing was taller. Your 3:42’s should improve this. I’ve read that some dyno comparisons between a 4L60 and 80 show minimal difference in parasitic loss.
I have to 2nd your statement on traction issues with the 3:73's and 3400 stall in my 80E. I just left a car show and for some odd reason the tires just decided to start spinning. Next thing I knew there was smoke and I was accelerating at a high rate 😁!!!
Weird how that happens, I have the same issue sometimes.
🤔
I don't like the gearing in either of these transmissions. With all the mods needed to fit a 4L80E under my 70 plus at least a $500 core which still might need rebuilt, bell housing adapter, a controller and an expensive converter, a TH2004R with mods is my choice. But as said, if you have the power where a TH400 or 4L80E is needed, their tall gearing and .75 OD gear in the latter's case won't matter as much. If anything you want the 2500 rpm highway rpm with a big cam. I figure 70 mph for me will be perfect, around 2200 rpm. I am surprised any truck converter will stall at 2000 rpm plus, most stall around 1500 rpm for towing. Probably because a 3/4 ton with a 350 needs the higher stall to get out of it's own way.
Thats a whole other story those th2004r.
Given im runing ls2 I think 4l60 and 4l80 are my options, and by reading here I think 4l80e is the way to go.
Given im runing ls2 I think 4l60 and 4l80 are my options, and by reading here I think 4l80e is the way to go.
TCI makes a gearset for the 4L80, gives a more TH2004R like 1&2.
If you use a stock converter, make sure the stall speed is at least as high as the stock converter from the GTO.
Thats what i was thinking. But how can you tell? Are there any markings on the converter as to check?
I also heard (not that I have any experience or knowledge) that same converter might stall at different speed on different engines.. notably bigblocks tend to stall the same converter at 300-600 rpm less than a small block.
I also heard (not that I have any experience or knowledge) that same converter might stall at different speed on different engines.. notably bigblocks tend to stall the same converter at 300-600 rpm less than a small block.
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