I have been told I may need a different TC for the Bronco. The lift on the cam is around .525 and was told that Crane Cams Dyno recommended a 2800 stall.

I have the factory converter in it now. What are the pros and cons for changing the converter to a 2800 stall?

 

Best I can tell is a factory TC hooks up around 1200 rpm. So jumping to a 2800 rpm converter seems like a big jump.

Will this cause drivability issues? Will it help or hurt mpg?

 

2800 sounds like a massive leap. I suspect that is higher than your hyw cruise RPM, and that could get old, quick.

I'd think 1500-1800 would be a lot more "livable" in the real world, while most anything higher would be better suited for the 1/4 mile.

 

Of course fuel mileage is going to take a hit.

How much time driving do you really spend below 1.200rpm?
How much time do you spend between 1,200 and 2,800 rpm?

Kind of imagine you were slipping the clutch that whole time.

 

You are going to have to follow the cam manufacturers recommendations. If you think it's too big of a jump, you need to change the cam. Your engine is not going to make any power down low with that cam, thus the reason for the higher stall. What are you running a 302? If so, that is even more of a reason to run a higher stall, that little engine needs to wind out to get that heavy Bronco moving. How big are your tires? What is the gear ratio in the axles? This all plays a part also. One little mis-match and it's not going to work very well.

Yes it will hurt fuel mileage. That cam is going to hurt fuel mileage. Larger tires will hurt fuel mileage along with the higher numbered gears in the axles. Big decisions to be made in the beginning, and you can't change your mind once you start unless you start over.

 

When my truck still had it's AOD, it also had a high stall converter that a PO had fitted......this was with an RV cam, but otherwise stock engine.

It was a pleasure to go back to a stock converter with the C6 swap - it gave positive drive & immediate response at low rpm, compared to the sloppy h/s converter.

The most noticeable difference was towing; particularly on a boat ramp where the h/s converter would need to high rpm to get the boat moving......then would drive, full-on.

 

Its a bigger job and probably a lot more expensive than changing cams but if you like that cam, and don't do a lot of heavy hauling or towing, you might convert to an AOD with the lock up converter. Higher stall and lockup converter might be a good combo for that cam in a daily driver.

 

Is the mpg hurt by not having a high enough stall?

 

No, quite the opposite.
It's constantly slipping.

But pay attention to Dave.
I don't know anything about cam numbers for Windsors.
If it locks up too early you will never be in the powerband.

 

A big cam plus high stall equals hard launches, just like the bronco in this thread https://www.ford-trucks.com/forums/1...ads-truck.html

Designed to launch in the meat of the torque band.

With the standard stall and a big cam it will bog down to a degree, how much depends on how the engine combo runs down low.
But from memory, you aren't running a huge carb so if this combo idles nicely down low and has decent torque under 2000 you shouldn't have an issue.
But I'm not a carby combo guru, so don't bet your life on my opinion.

I do know that pushing more power through stock converters makes them appear to be higher stall, but that's because you are working the fluid harder. So maybe give it a go as is, but use the synthetic trans fluid and fit a large trans cooler.
If you don't have a lock up convertor your fuel economy will always be less than optimal.
Certainly Dave's got some great advice listed already about the combo.

 

Dave what I am concerned about is real hard take offs that would be a con for driving in wet or snowy conditions.

I have a huge cooler. It's a condenser for the AC on one of these trucks. I just dont want it to be like driving a funny car around town.

Also it's a 351 W Dave.

 

With that cam and the stock converter you aren't going to have hard launches. The converter doesn't let the engine wind up into its power band so it won't rev quickly.

I agree with Brad - the engine idles reasonably and isn't low on vacuum so I don't think it is going to have a problem with the stock converter. But, what do I know - its not an Edelbrock.

 

It doesnt like to idle in gear. Thats its weakness.

If I change converters I am going to change to a 2800 like is recommended or it stays stock. I dont want to change it or buy it more than once. So I want to put some thought into the notion.

I am trying to get educated on TC's and kick this project around some.

 

Does the engine idle the way it is supposed to idle? Has everything gotten sorted out?

 

The engine will idle in park and no the weather has kept me from the DSII swap. However, I did go pick up my re curved dizzy that was done at a place I lost confidence in during a phone call discussing Edelbrock carbs. I sure hope they know more about dizzy's than carbs.