4L80E behind a 5.3
 

Any reason not to do this? I know the 4L80E is heavy but is it goign to rob some power from the 5.3? Planning to run a stock long block with a mild cam, headers and CAI and a 2800-3000 stall. Found a 4L80E core local for $150. I know 2 transmission guys so getting it built isnt a problem.

Re: 4L80E behind a 5.3
 

Go for it. 60e trans are a consumable item if you get on it hard in stock form. Just be sure to wire harness as a 80e and use applicable PCM file. I stopped using 60e in my swaps for reliability issues.

Re: 4L80E behind a 5.3
 

You can beat on a 80e in stock form and try pretty hard to break it.

Re: 4L80E behind a 5.3
 

If you were to dyno the same vehicle with a 60e vs an 80e, the 60e would have a little less parasitic drivetrain loss; the tradeoff being that the 80e is far stronger, enough to warrant a little extra loss.

When you start making big power, that few hp loss is worth the strength. The same applies to rear ends as well (i.e 10bolt vs 12bolt)

Re: 4L80E behind a 5.3
 

Can you do it? Of course you can. Do you need to do it? Probably not. Does it work with your budget over buying a 60e? If so go for it.

In my opinion if you have no plans for big power I would go with a 60e. They are a **** ton lighter, smaller, and have a shorter first gear.

If you stay within there limits they are just as reliable as the 80e.

Not trying to sell you on one or another but if you are not putting down some serious power then a 60 is a much better choice!

Re: 4L80E behind a 5.3
 

Can a 60e hold 450hp? Is it just a re-pin of the trans harness to run a 80e? I was wondering the same thing as I just got a 5.3/4l60e that I'm putting in my 40 Ford. Plan is to turbo it and aim for 450-500hp. If the 60e is not going to live, I'd rather build the frame to accept a 80 now.

Re: 4L80E behind a 5.3
 

Totally different case and I would go 80e on any turbo build. The main reason is most people end up wanting to put more power down eventually with the boost bug.

In the end it's more of a question of the torque. At 450 you would most likely be around upper 300-low 400 on tq depending on the cam and right at the limit of a mild to fully built 60-65e. Of course I have seen plenty of built 60s stay together with over 500 ft lbs but just as many come apart. With boost or nitrous the trans takes more of a beating due to the rapid increase in power.

It's pretty much a repin to add the speed sensor and flash to go from a 60 to 80.

I'm sure Clyde will chime in too with some knowledgeable feedback, as I am sure he has done a ton of both transmissions.

Re: 4L80E behind a 5.3
 

Ok, thanks for the info. A lot of people I know say the 60 will live but I can't honestly say I'll not drive it hard and want more power once it's together. Everything else I have keeps progressing. I'm sure this would be the same. Are there any years 80e's that are better to start out with over others? Thanks for the help and info.

Re: 4L80E behind a 5.3
 

I would personally go with an 80. In completely stock stocks the 4l60e doesn't often live past 100k. If you drive hard and have extra power the 60 will die a quick and expensive death.

Re: 4L80E behind a 5.3
 

99-01 have the better sprag in them but if you are rebuilding it, anything 99 and up will work. Myself I like the 01 and up because I always go through them and they have the newer od setup.

Re: 4L80E behind a 5.3
 

Does the 67-72 cab need a high hump for the 4L80e to fit? And is there anything that need to change on the 5.3 so the 4l80e will work except from the pcm flash and wire harness mod?

Re: 4L80E behind a 5.3
 

Yes you will need to have a high hump. If you are layed out you will have to make a few additional mods to the hump and floor. As for the swap you will also have to figure out what converter you are running. If you plan to run a stock 80 you will need the flex plate and spacer from the 6.0l. If you are going to a custom converter you can have the cover done so you can use the stock 60e stuff.

Re: 4L80E behind a 5.3
 

It may depend on where the engine is mounted, but my blue 72 had a 6.0/4l80e and had the low hump and it fit fine. There are pics in the build thread in my sig if you want to see where the engine was, but it was close enough to stock that the fan fit the fan shroud.

Re: 4L80E behind a 5.3
 

If you change the wiring harness and plug on the side of the trans (part of a full case rebuild) then you can use the pre 99 80e's.

Re: 4L80E behind a 5.3
 

I'm usually hesitant to engage in threads like this......

Everyone know's I like 4L60E's, When built right they can handle 450-475 rear wheel torque for a LONG time. Past this you get into hard part stressing that is just is not worth the hassle or expense.

However you have certain people that can burn up a 4L60E with 350 ft lbs in a month, Of course when they drive it's like 24hours of LeMans with stop lights, Too many repetitive WOT 2-3 Up-shifts, 3-2/4-2/3-1/4-1 Down-shifts will overheat the 3-4 Clutch!!! And cause Friction failure.

4L80E....Great unit! Dual Feeding the Directs, Lube to Line mod, Boost Valve, HD Intermediate Snap-ring, Fix the AFL & TCC regulator leaks, Set end-play, Blueprint clutch clearance & feed hole sizes....can handle 800 ft lbs.

What nobody talks about is what a 4L80E robs under the curve, Not just ratios, But the weight of the drums. I can tell the difference! The more power you have....The less this matters.

Re: 4L80E behind a 5.3
 

Must be. I know on mine with Nates crossmember there is no way its fitting under the low hump.

On a side note yours and acks trucks were the ones that pushed me to an LS in mine. Loved how clean it was! Have you seen it since it sold at auction?

Re: 4L80E behind a 5.3
 

Cline I knew you would find your way to this thread. For some reason I just noticed my autocorrect turned you in Clyde lmao. I am on the same page as you. The 60e is a better choice for any mild na application.

Re: 4L80E behind a 5.3
 

I don't have a preference really. I don't have a transmission yet and found a core for $150 so I thought I'd ask. Not sure if I'm going to pick it up or not though. It's currently mu daily driver with a 305/700r4 and the trans is starting to go so might have to hold off on this project for a bit.

Re: 4L80E behind a 5.3
 

This works amazingly well as a fill-in-the-blank statement!

Re: 4L80E behind a 5.3
 

So whats wrong with being call Clyde??

Re: 4L80E behind a 5.3
 

Ha-ha, nothing if you were who I was talking about. I think auto correct likes Clyde and not Cline since its the one that made the switch on me!

Re: 4L80E behind a 5.3
 

No high hump needed. I've got a low hump and the 4L80E fits with tons of room. Easy to work on, heck I can even access all the bellhousing bolts with minimal fuss.

As for power robbing, in theory, sure. Over on ls1tech there's multiple threads of track results after switching from 4l60e to 4l80e and there's no change. Several went faster due to the more favorable ratios. Bottom line....if a 4L80E fits, in my mind there's no reason NOT to run one.

Re: 4L80E behind a 5.3
 

And here we go with the great forum debate.

In the end the difference is in the converter and the power the motor makes.

Re: 4L80E behind a 5.3
 

Haha sorry about that. Didn't want to start a debate. You're 100% right anyway. The converter is the key. I still stand by my statement though, for the average Joe trying to run 11s or 12s just install something reliable. The 4L80E is tough to beat from a cost/toughness/streetability standpoint.

Re: 4L80E behind a 5.3
 

Haha no worries, it was bound to happen.

For sure I wont argue it, I love the 80e's. Just like to make it clear that a 60e for the right price isn't a bad deal for a mild built LS.