Hi olds family,im the new guy and just wanting some answers, i believe an olds 455 bb will fit in my 67 cutlass supreme body(330 5.4ltr) but will my 2spd powerglide be strong enough for this 7.5ltr motor ,what about my diff do i need to upgrade...everyone's help would be much appreciated, im a plumber i have no experience with engines but i am a keen and quick learner....and need a hobby, thanx.

 

I personally do not have any experience with the powerglide, but if the guts are the same as a Chevy, it's a preferred tranny for many drag racers. I'd definitely get it rebuilt and upgraded before installing. Good luck.

 

I think the 455 should bolt right in. I wouldn't waste money on a "powerglide" 2 speed. Use a TH400, its more rugged and has a better spread of gear ratio's with 3 speeds.
Rear differential will probably be fine, but check with member "Monzaz" on this site. You'll certainly want an "anti spin" rear end, possibly a different final drive ratio.
....just my 2cents worth

 

You transmission is not a Powerglide, nor does it use powerglide parts. The 67 Cutlass was available with and the 442 came with a 400. Your Jetaway (ST300) transmission will bolt up and work fine as long as you don't whip it like a rented mule. You also have a switch pitch or variable vane torque converter with a switch attached to the throttle linkage on the firewall. As the others said a T400 is probably the better choice, but then you would need a drive shaft in addition to some other minor parts also.

 

I did this swap and it was a piece of cake, I would DEFINITELY go with the turbo 400, whats the purpose of going to a big block if you cant play and have to baby it. Even with the 2.78 rear that was in the car, it was really strong. I went with a 3.23 rear ratio and lots of smiles.

 

You will need the 455 flexplate as the one from the 330 will not bolt to the 455 crank.

 

Since this question will eventually come up, DO NOT buy "455" motor mounts. Use Anchor P/N 2261 (or equivalent) which will bolt to your existing frame pads.