4.3L vs 5.7L Torque Converter Stalls?

[98chevy2500SS]

Got the 4.3L out of my 97 and I'm going to be installing a 350 in it soon. I've been reading the torque converter stalls are different between the V6 and the V8. Question #1: is there going to be a problem using the V6 torque converter? I plan on keeping the 350 engine stock (stock cam, crank, etc.) and putting a Corvette servo in the 4L60E. Question #2: the truck didn't come with an aux trans cooler from the factory, should I get one since the V6 stall is higher?

 

[GoToGuy]

You could always look in parts book. Do they list the same part for both setups? How do you know it has higher stall? The term " you've been reading", is that, you read in Hydramatic Transmissions book, or GM service? Just be careful with your research, there's a lot of incorrect info that keeps getting repeated and passed on.

 

[stutaeng]

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!

 

[letitsnow]

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.

 

[L31MaxExpress]

The 4.3 S10 converter is excellent. I had one behind the L31 in my van and loved it. Much better get up and go compared to the ~1,397 rpm factory converter. Drove about like the stock converter at lower throttle angles.

4.3s used the higher stall speed to help crutch their relative lack of low speed torque.

 

[letitsnow]

The 4.3 S10 converter is excellent. I had one behind the L31 in my van and loved it. Much better get up and go compared to the ~1,397 rpm factory converter. Drove about like the stock converter at lower throttle angles.

4.3s used the higher stall speed to help crutch their relative lack of low speed torque.

What was your cruising rpm? The 4.3's I drive - the cruising rpm in OD ends up being 1600-2000 rpms. Too close to the stall...

 

[L31MaxExpress]

What was your cruising rpm? The 4.3's I drive - the cruising rpm in OD ends up being 1600-2000 rpms. Too close to the stall...

1,950 @ 70 when it had a 65E and 3.42s with stock height tires. You should be in lockup cruising. The S10 converter would flash 2,700 behind the 350. Light throttle it would hold lockup down to about 40 mph in OD and about 1,200 rpm.

 

[letitsnow]

1,950 @ 70 when it had a 65E and 3.42s with stock height tires. You should be in lockup cruising. The S10 converter would flash 2,700 behind the 350. Light throttle it would hold lockup down to about 40 mph in OD and about 1,200 rpm.

Keep in mind that you are way better equipped than most in the tuning/programming area. Most of us are trying to run this junk with stock/close to stock motors and tunes.

 

[stutaeng]

I'm guessing gear ratio needs to be brought into the unknowns here?

Edit: oops, didn't see the last few posts.

 

[L31MaxExpress]

Keep in mind that you are way better equipped than most in the tuning/programming area. Most of us are trying to run this junk with stock/close to stock motors and tunes.

Fair point. I have found tuning the transmission side alone often results in bigger gains from the driver seat than the engine.