[1BadAss70]

I've recently to go with one of the powerful 454s from Mark at Vortec for my 70 SS.. Now that I've decided on my engine, i would like to know what are some of the best transmission are out there for a engine that produces 620 to 650 for my highway cruiser??
Thanks for the help!!

 

[540ChevelleSS]

Stick? Auto?

 

[VinceS427bb]

what do you have now???
street, street/strip?
what do you think you want?

 

[davis95]

If auto...Turbo 400 if you want a 3 speed, 4L80E if you want an overdrive transmission.

 

[edspdog]

Turbo 400, 4.10 rear ratio. gear vendor hands down.

Have a good day, Ed.

 

[edspdog]

and a 2800 stall.

 

[1BadAss70]

Morning Guys,
It will be auto matic.
I'm going from the th 400 to a automatic with an overdrive.
For street car purposes.

 

[94ttss]

Put a gear vendors behind it and call it a day.

The 4l80 is nice but by the time you buy the trans, converter, controller, shifter, mech speedo housing and make it fit your way ahead with the gear vendors.

 

[Guest]

The problem with the TH400/Gear Vendors is that you don't have a lockup converter. The 22% overdrive ratio isn't spectacular either.

If you are using a stock or near stock converter, this wouldn't be too much of an issue, but anything with much stall and the 400/GV setup is going to build heat.

I had a variable pitch converter TH400 and Gear vendors in my '69 Chevelle for a short while. After dealing with "real" automatic overdrives for years and doing conversions it would be low on my list of methods to get OD. And having OD is important in my opinion for any car that will see mileage, whether it be a manual or automatic.

The GV doesn't fit as well as they lead you to believe, and I had driveline angle issues, even with it as high as I could get it without cutting the floorpans. Part of that issue is due to the extra length causing a SHORT driveline, which makes the angles more pronounced.

I would rather rebuild a 700-R4 or 200-4R every year than use a Gear Vendors.

They also downshift fairly harshly.
They may work better behind a manual trans.

 

[Orr89rocz]

4L80e should do that easily without much done to it. Converters are abit more money that th400 but worth it for lockup

A well build 700r4 should also handle street duty As long as you dont romp on it constantly. Its gonna be a pricey rebuild tho to hold it reliably. But i think steeet rolling starts are softer on the trans than hard digs, but during the shifts is also hard on the clutches. I would set it to shift abit softer to help save trans? Could help i suppose