Hi Guys!
I am restoring a 1972 cutlass S 2 door. I am replacing the 350 with a stock 455. I want to replace the TH350 transmission with an overdrive, either a 700 4R or a 200 4R. I currently have 2.73 rear gears, and I am wondering if this rearend ration will work well with the 4 speed. This car is going to be a driver, not a drag car. Any opinions are greatly appreciated.

 

It should work well for a cruiser.
The 7004r will need a chevy conversion mounting plate, and the driveshaft will need to be shortened.
2004R should bolt to the motor , but your transmission mount and crossmember may need to be moved back or swapped out for something else.

 

Neither the 700R4 nor the 200-4R will survive in stock form. Since either one needs to be modified, the 200-4R is the easier swap. Your stock driveshaft will work fine. Your stock crossmember will also work fine, though you will need to move it rearward. Your frame is already drilled for this rearward location since it is the same as used on the TH400 that was available in 1972. You will need to get the throttle vavle cable and bracket from a 1980s Olds with the 307/200-4R combo.

 

Thanks for the correction, Joe.
I do believe a 700r4 could survive fine if it is just a driver, though.
I'll have to get back to you guys on that one.
We just put a motor that ran 12.40's in front of a 700r4.
I'll let you know the outcome after the racing season is over, or as soon as it shatters into pieces.

 

With me I like having the trans as the weakest link as the labor and cost of a replacement are relatively cheap.

I'd rather break a trans than the engine or rear end ...

 

X2

 

Thank you very much for your comments. What kind of modifications do you suggest I make to the 200 4R to make it more durable?

 

http://www.cpttransmission.com

Norm

 

I bypass the radiator and plumb the lines directly into the biggest transmission cooler I could find ...

Heat is the enemy ...

 

some reading

http://www.turbobuick.com/forums/tra...ing-2004r.html

 

I'm checking the linkbacks. I am checking out interchanges like universal bell housings when this popped up ...

Kind of takes the hassle out of shifter locations...

...

 

Try a 4L60 should be reasonable on price, think the final drive ratio was around 0.60, dont forget to replace your spedo gear, might want a tranny shop to mach it up.

 

I use the guy that calibrates the chip speedos' ...