How much torque did 428CJ’s really make? Was it 4 or 5 hundred ft/lbs? The Ford T & C top loader was the toughest factory gearbox of that era but I think you might break it if you hook up. You’re likely double the engineered capacity.

 

From what I understand the "hemi" A833 was the big man on the block.

 

Tire size and rear suspension will have a lot to do with durability of any transmission.

 

This ^^^^

Wheel hop or other impact loading will cause a lot of damage with even 500 foot pounds.

If you really foresee anywhere near 1000 foot pounds go to any number of aftermarket racing transmissions and leave the old Detroit stuff for collectors.

 

You’re going to want the big input shaft.

 

TWSS!

 

Will hold everything a flathead will throw at it.

 

Post #3 is the right answer

 

With the big shaft and street tires it will last a good long time.

 

jerco or a g-force
oem top loaders fail at 525 h/p if it truly hooks. they lasted back then as tires sucked. todays street tires are better than most slicks back then.

 

I bracket raced a small block ford with a top loader. Held up until the 30 lb. flywheel got installed. After bench pressing a third trans i put an automatic in it.

 

A true street tire will be ok. You put something sticky on there and it's gonna be a grenade.

 

STOCK wide ratio small in/out toploader in my car. 3300 lbs with driver. Best 60ft of 1.39 seconds.

Your TIRES will be the 'fuse' in the system. If you don't get much traction, your trans will be a lot harder to break. Now, once you are in the higher gears, 1000 hp or ft/lbs will still put things to the test, especially if you shift hard.

Not a fan of the close ratio trans. Worked fine to attempt to hook up the hard 6" wide bias street tires of the era, I guess... lol

 

This being said, the T56 6 is the ultimate STREET trans. Super strong, and they shift really well. Overdrive is also nice. The most powerful new cars use this unit. Plenty of 1000 hp late model vehicles drag racing with this trans on slicks. Hard to beat. Trans tunnel mods MAY be required.

If you have your heart set on a toploader, you can now buy the big input shafts for the wide ratio transmissions. A big main/output shaft is also available. The big input is 1-3/8" instead of 1-1/16". The big main/output is 31 spline instead of 28. Much larger diameter. The small/28 spline unit uses a C4 yoke. The big/31 spline uses one for a C6. Of course, billet/high performance yokes are available for both. I kept killing Spicer 28 spline yokes, and had to upgrade to a Mark Williams unit, as they were the only ones who sold them a couple decades or so ago. Still using it!

Good Luck!

 

If its a big in ,and factory its a 2.32 ratio, wide was 2.78 ratio, they only made 1 wide big in top loader 69 ford gal-x-e. you can buy wide ratio big in put,and parts to switch it to a 2.78 ,

 

I forgot about Rockland Standard Gear Transilla: http://www.rsgear.com/products/performance-race-transmissions

 

I’ve alrwady installed the aftermarket big input. Other than that it’s stock. I’m not going to be drag racing the truck. I’m mainly going to be fucking around with it. Burnouts and stuff like that. It does run a 275 rear tire and 4:10 rear gear.

 

Why build a 900+h/p engine if you just want to smoke the tires in a p/u. a honest 350 h/p will do that until you lift.