Technical auto transmission for 55 gasser

A 3 speed auto is faster than a 2 speed you can stay in your power band longer that is why pro stockers added more gears. With a auto trans the converter is very important when building a stocker we have worked with a converter company using as many as 5 different stall settings the find the fastest.

 

How about an old Hydro. Flat pan with chevy bell and furnaced brazed torus.

 

Have your Friend reconsider on a Trans Brake. If you go for a high RPM stall, the brakes may not hold the car in the lights

 

If it' a gasser how about a turboclutch?

 

We still don't know much about the engine itself. The manifold, carb, and duration @.050 would tell us a lot about what RPM he needs to hit the converter from to launch it as hard as possible.

 

I’d like to I know more about this

If I have a 2800 stall with a [email protected] cam and 3:73 gears with a powerglide what would the best way to launch be?
In my 36 if I load the converter I make nice black marks but how do you not spin?

 

Leave a stick in it. find a grandson to drive it. All real hot rods have three pedals.

 

First of all, are we talking at the strip or on the street?
There's not going to be any traction on the street, compared to a prepared drag strip.
When you stall it up, you're also taking all the travel out of the suspension, thereby losing a bunch of weight transfer.
A Powerglide depends on converter flash to make up for the lack of 1st gear. It may work better by booting it from a high idle. This , of course, depends on how the carburetor is set up...which is what type ?

 

Put me in the three speed trans group. I don't think he has enough power to weight to use a Powerglide. A built T350 or 400 with a high stall converter would be the direction I would go. A good trans and torque converter builder will take his specs and specify a good combo for him. Check with TCI, B and M, etc.

 

Holley 670 street avenger on the street

 

Okay, had to look it up. Looks like a vac. secondary, so you should be able to set it up so it leaves clean and crisp from a high idle. Somebody else would have to help you with Holley part numbers.
Generally, leaner is meaner from a high idle.
If you're serious about this though, you might want to invest in a set of DOT sticky street tires. They're not going to turn a city street into a drag strip, but they will help some anyway.

 

Dooley you may need to work on the rear suspension of your car. We don't know what you have.
But now we are getting OT.

 

Agreed
The 55 sounds like it's going to be really cool

 

I had a glide in this car but it didn't last behind the HEMI so switched to a 727. No transbrake on eather . Rear disc held it at 3500 to 5500 rpm foot braking.

 

Thanks ,salty. Forgot to mention that. If you don't have some kind of device to cause the car to separate and plant the tires, you're fighting an uphill battle.

 

We had a 64 corvette coupe. 327 300 and a powerglide. 3,070 lbs. That was a scootin dude! Stab it from idle. Shifted out of low by itself about 70 mph. You could hold it in lo to 90 mph. I would put a beefed glide with a convertor and shift kit and never look back. JMO Lippy

 

I don't know , lippy. We still haven't seen a picture of anything to get a feel for this nostalgia "vibe". No et's to go by.
I figure if he's babying it off the line at 3000 and granny -shifting it, well yeah, it'll probably go faster with an automatic.
But if he's running it to it's potential with a stick shift, he's going to be awfully disappointed with a Powerglide.
That's about all I can add at this time.

 

All of the GM transmissions will shift at any RPM you want them to.
All noted above will work well (T-200, Power Glide, T350, T-400).
To handle 500hp/500ft.lbs of torque, shouldn't cost near $5000 for any of the list.

**T-200 (3spd) will rob the least amount of engine power and is the lightest of the bunch.
**Power Glide would be next in power loss, cost, weight. BUT CAN cost over the $5000 noted above for the top-o-the line Power Glide. But it doesn't have to to control 500 ft.lbs.
**T-350 next.
**T-400, will rob the most power, and is the heaviest...stock. Though, for the $5000+ noted above, can be the best choice overall.

But if you don't want to spend that much, look into my list above in order.
Not pushing anyone...but here's one place for the T-200, with a good NHRA track record of building a good race trans. for a reasonable cost - https://www.scottmcclayengineering.com/

Mike

 

Go with a cheap 400 and use the money to buy more motor.

 

Bought a running/driving 65 Impala SS 396/Turbo 400 for $150 in 1976 for my racecar trans.
You won't see those "cheap" days again!

 

Weight should be one of your determining factors in your trans decisions. Also if you are foot braking or trans braking.
With only 425 hp. I would have someone build a th350 with a aftermarket sprag and run at least a 4800 rpm stall to get it rolling. Also run a locking dipstick tube as some th 350 will puke fluid on the top end when you lift.
I ran a th400 with a trans brake and a 4800 rpm stall torque convertor behind a big block for 2 seasons in a 3700 lb 70 Malibu . The only modification's was red clutches and a deep pan. That car ran 10.90's .