Charly9g

Hi all. What is the best choice to put behind a mild 455 BB. I'd like a smoooth cruiser that i can do 70-80 mph on freeways. It's going into a '57 Olds 88! The 455 will have a mild build concentrating on low end torque. This car has a 200r4 @ the moment. is the 200 a decent trans? Worth building? many thanks in advance.

cutlassefi

The 200-4R is a great trans. When done right it will take just about anything you throw at it. Remember these are the same trannys pushing 9 second Buick GN's.

citcapp

Correct just make sure it is built right or the 455 will tear it up

Charly9g

Thanks . Think i'll upgrade to a 4L70. has anyone hd any experiance w/these? Thanksagain.

joe_padavano

The only 4L70 is the 4L70E, which means in addition to the trans and adapter plate for the BOP bellhousing, you'll need the $500-$1000 trans controller box and associated engine sensors (TPS, MAP, and probably RPM tap on the distributor).

The only non-computerized GM OD automatics are the 200-4R and the 700R4/4L60 (not to be confused with the 4L60E). Given the choice between those two, I'd go with a beefed 200-4R. The stock 700R4 isn't strong enough for a BBO either. Keep in mind that the 200-4R uses the same crossmember location as the TH400 and the same driveshaft as the TH350. The 700R4 and all the electronic transmissions use completely different crossmember locations and driveshaft lengths, so you'll be looking at drilling holes in the frame railes, possibly building custom e-brake cables, and definitely building a custom driveshaft.

citcapp

You would be better of sticking with the 200-4R. it is a tight fit in the stock transmission tunnel and the length ok to clear the "X" frame cross member for the front U joint. the 700 is a larger transmission and I believe you will have to rework the tunnel and have possible length problems. I know the turbo 400 just clears the floor on my 57 with a 455 by about a 1/2 to 3/4 inch and the 200-4R is about the same size

olds 307 and 403

You are barely upgrading going to the 4L70E. Plus the need for a TPS, trans controller and expensive housing for a cable driven speedo. The 2004r with a few billet parts will hold up. Guys who know both prefer the 2004r. The only reason to use the 4L60-65-70 series is for 4x4. The 4L80E is based off the TH400 and is much stronger. It is only one of the electronics worth considering but far from cheap.