4.3L vs 5.7L Torque Converter Stalls?

[98chevy2500SS]

On the 4.3/4.8/5.3 generation of trucks, a lot of guys will swap a yunkyard 4.3 torque converter into their 4.8/5.3, because it's got a higher stall. A budget converter upgrade, if you will. Not sure how that applies to the 4.3/5.7 generation or if you are wanting a higher stall speed.

More importantly, make sure you get the right converter compatibility with the transmission. What year is the transmission vs truck?

Install a cooler, no matter what!

The truck is a 1997 Chevy C1500 with the original 97 transmission in it. I plan on putting a 6 lug 14 bolt rear axle in it with 3.73s. Current gear ratio in the stock 5 lug rear end has 3.42s.

 

[Supercharged111]

I think the V6 trannies got fewer clutch packs as well, but don't quote me.

 

[L31MaxExpress]

I think the V6 trannies got fewer clutch packs as well, but don't quote me.

While that is true on 700r4s, I have heard that it is not on 4L60Es. The V6 700r4 had one less clutch in the 3-4 clutches.

 

[Supercharged111]

While that is true on 700r4s, I have heard that it is not on 4L60Es. The V6 700r4 had one less clutch in the 3-4 clutches.

I would say that's good news for the OP, but at the end of the day it's still a 4L60.

 

[Dropped88]

On the 4.3/4.8/5.3 generation of trucks, a lot of guys will swap a yunkyard 4.3 torque converter into their 4.8/5.3, because it's got a higher stall. A budget converter upgrade, if you will. Not sure how that applies to the 4.3/5.7 generation or if you are wanting a higher stall speed.

More importantly, make sure you get the right converter compatibility with the transmission. What year is the transmission vs truck?

Install a cooler, no matter what!

We run a torque converter from an I6 4.2L from a trailblazer. Its a direct swap

The small block generation 4l60e has a 298mm input shaft when the LS 4l60e has a 300mm input shaft

 

[stutaeng]

We run a torque converter from an I6 4.2L from a trailblazer. Its a direct swap

The small block generation 4l60e has a 298mm input shaft when the LS 4l60e has a 300mm input shaft

I didn't know the I6 torque converter also worked on those transmissions, but forgot they also got the 4L60e...

Agree on the 298 vs 300 mm input shaft. The 300 mm shaft version from the 99+ 4L60e dealt away from the V6 vs V8 internal differences from what I gathered, at least in the Silverados, they are all the same. The torque converter was supposed to be better, along with the friction material and I can't remember what else.

My 99 NBS ECSB 4.3 had the LS-style 4L60e. The transmission had the 12 o'clock bell housing bolt hole, the 4.3 did not have a bolt hole there.

I wonder what 4L60e transmission setup was mated to the late 5.7 Vortec in the Express vans that went up to 2002? Probably the same?


I believe LS style transmission requires some special flywheel to mate to the SBC?

Well, it doesn't matter. It seems like OP already has a tranny ready to go...

 

[98chevy2500SS]

Sounds like the V6 converter should work, just more pep at take off?

For the aux tranny cooler, should I grab one off of a half ton or a 2500/3500?

 

[Nad_Yvalhosert]

Sounds like the V6 converter should work, just more pep at take off?

For the aux tranny cooler, should I grab one off of a half ton or a 2500/3500?

I've only seen one size factory auxiliary
cooler for the 400's. Get that one, and all new hard lines.

Edit: I just checked Rockauto. They list the same part number for the 1500 as the 3500, both gas engines:

GM GENUINE 89022535

 

[df2x4]

FYI, the TruCool M7B is a pretty significant upgrade from the factory AUX cooler and will fit just fine with some minimal trimming of the factory mounting brackets and a couple fitting adapters. There's a thread on that subject here.

https://www.gmt400.com/threads/how-to-factory-auxiliary-trans-cooler-upgrade.18104/

The TruCool M7B is the exact same part as the B&M coolers mentioned in the OP, they're all made by the same company (Long Manufacturing Inc). It's much cheaper than the B&Ms though.

I am probably the minority on this - the 4.3 vortec does come with a higher stall tq convertor, as far as I can tell/and have read too. It shouldn't have. The 4.3 makes no real power up in the higher rpms, it is a torque builder, similar to its big brother - the 5.7.

Every 4.3 vortec powered truck/van that I've driven, I am always thinking - this tq converter is way too loose - it doesn't match the characteristics of the motor. It is always unlocking/locking at weird times. Somebody in a cubicle probably decided that it was the hot ticket. It is not.

If I have to replace the tq convertor in my 4.3 powered s10, it will get a LOWER stall convertor.

On a somewhat related note, I used a V8 torque converter when I 4L80E swapped my V6 truck as that's what came with my junkyard 4L80E. (Donor truck was a '97 C3500 with a 350.) It works just fine, but I feel like a slightly looser converter would be beneficial. After the swap I can't really get the truck to do a burnout on dry pavement, it would do so almost effortlessly with the 60E and V6 converter.

 

[letitsnow]

Sounds like the V6 converter should work, just more pep at take off?

The only down side would be if your cruising rpms are too close to your stall rpms, it might keep engaging/disengaging. If it does that, you can just shift to 3rd like I do in the s10.