Sell the 4L80 and use the funds to build it to a stout 4L65 standard.

 

Although a stock 60 can never beat a stock 80, with a few modifications a 60 can out perform an 80 on different levels.

Sent from my SM-G998U using Tapatalk

 

A 60 will never be as good as an 80 period.

That being said, a cammed 5.3 don't mean much to me. Are you doing a hot cam or just a simple one that's not much bigger than stock? are you going to be racing stop light to stop light often?

If its just a daily driver that you don't beat on and the cam is just to get a little more out of it will likely be okay.

 

Tell that to this guy.

Sent from my SM-G998U using Tapatalk

 

It is a relatively medium project to put the 4L80 in, need the new harness, crossmember and tune.
I would just run the 60.

 

Without getting into another argument over these two trans, I stand behind my statement.

There is a reason racers get these level 2-10000 4l60s just to swap a 4l80 after 1-2 summers of racing.

 

 

The 4l80 can be built into an absolute monster of a trans. They are pretty rock solid in stock form for stock applications.

The 4l60 can be built to be strong, but it'll never match up to a built 4l80. Stock for stock I'd take a 4l80 any day. Far superior transmission.

However, it isn't exactly a bolt in swap. But it is common, so there is lots of info out there on how to do it.

 

Thanks for the replies, I was running a Summit 8701 cam in the 4.8 with LS6 springs, planning in the same with the 5.3, so it's not the nastiest build, I do beat it hard sometimes, and it does see the odd heavy load, still gets used as a truck, and it may see more power someday but who knows, it seems like the Sonnax parts to build a strong 4L60 are expensive enough, which is OK, but I question if maybe 4L80 would do the same job for less, maybe just a rebuild, valvebody upgrade and slightly higher stall convertor vs a complete performance build, I also feel like a 60vs80 is like a TH350vsTH400 in that the smaller trans take less power to turn, and the 60 has the higher overdrive, so would there be an advantage to the 60 for economy, and power loss, I'm a mechanic and do my own tuning so other than driveshaft fab I can do the labour with the cost of my time, drag racing against a similar truck, one with an 80 and the other with a 60, would a 60 have a lower ET? This is what keeps up at night

 

Thanks for the replies, I was running a Summit 8701 cam in the 4.8 with LS6 springs, planning in the same with the 5.3, so it's not the nastiest build,
...so would there be an advantage to the 60 for economy, and power loss, ...would a 60 have a lower ET? This is what keeps up at night

Yeah, the 60 takes less power to turn and has better gearing. A built one is fine for 500 and more horses. Much more and the 80 would be a better choice but motors with that much power aren't daily driven for long.

 

I think I'll stay with the 60, but I'm going to price both options, the 60 that came in my truck worked great, I had the line pressure ramped up and had the WOT shifting parameters to use 1st and 2nd to the fullest, I had it shifting out of 1st at 7000rpm, then at 7200 with the 4:56 gear, I know that revving that high it is out of the rpm range of the cam and doesn't make perfect sense on paper, but with the stock converter and many other factors it seemed to pull best like that and die down less on 1-2 shift, plus it sounded wild, and I built it to beat it, I think the pump failed in my original trans from the excessive RPM, it suddenly lost every gear after a 7200 rpm 1-2 shift, I put another 60 in it that was recently rebuilt, from a V6 van, was excited for the 6 cyl converter, but it slipped sometimes so I never poured the power to it, first Dex 3 transmission I filled with Dex 6, so that compatibility argument is in my head, now that the engine seized and the trans is out I want to make it right, I figured the oil pump in the engine failed from high rpm as well, but pulling the motor this weekend, it had coolant in the oil, upon disassembly it was the head gasket that had failed, at the driver's side rear, this is the 4th time that this has happened to this truck, I bought it after the 3rd time, this motor was the first one with the newer style MLS head gasket that failed, so they don't last forever either, I swapped the cam and springs into the 4.8 with the motor upside down on a stand, as cheap as I could, that was cool, but I'm going to go through this 5.3, at least all new gaskets and oil pump, make it decent, as well as the transmission, I think I'll give up on the 7000 rpm thing and run something more like 6500

 

I had it shifting out of 1st at 7000rpm, then at 7200 with the 4:56 gear, I know that revving that high it is out of the rpm range of the cam and doesn't make perfect sense on paper, but with the stock converter and many other factors it seemed to pull best like that and die down less on 1-2 shift, plus it sounded wild, and I built it to beat it...

Did you measure the performance of these settings or use the butt dyno?

 

At 7k, you risk all kinds of crap if you're not built for it.

Sent from my SM-G998U using Tapatalk

 

Holy sh.. 7000-7200? You should be more shifting at like 5600-6000

 

Use a 2.84 carrier if you're worried about rpm drop. Instead of 7000, you can shift at 6200

Sent from my SM-G998U using Tapatalk

 

I don't think you are still making power at 7k even with your cam lol