Hot Rods Calling ALL Pontiac Guys

Hey Everyone,
I'm in the process of working on a 1955 Pontiac Chieftain. I want to do an old school hot rod out of it. It currently has the 287 in it, it runs good and everything but I'm looking to put a bigger engine in it. What engines will bolt in with no modifications? I've heard 55-62 will bolt right in and hook up to my transmission can anyone verify this? I'd like to put a 347 or 389 in it.
Thanks for the help.

 

55-60 bolt pattern is same.
55-56 hydro bolt on.
56 was transition year and im pretty sure newer dual couplin hydramatic had different Size Crank center snout.

 

With crankshaft or fluid coupling mods you can bolt on 59-60 389 engine.

 

So 55-60 engine will bolt right in but the transmission will need to be changed?
Just making sure I’m following

 

We hope you have the hydro - the early selector 3 speed isn't much of a trans for anything but a stocker.

 

What transmission does your '55 have?

The '59 389 has one-year-only forged steel rods, which is kinda cool.

 

Wallace Racing has a good interchange chart that covers this.

 

'55 to I believe '58 have front mounts for the engine, not sure if the 59-60 do. You might have to do some work on that end.

 

pretty sure it’s the hydro it’s automatic column gear selector