Hello Caddy Fans
I'm looking into changeing my transmission in my 78 caddy. I changed my engine from 425 to a 472. I want to know if any other trans I can bolt up to this engine. I what to try a 5 speed trany it has 3 speeds now. I'm thinking if I can put a 5 speed with over drive It would help on gas mileage.
Any body Have any Ideas please let me know.
Thank you!

You can install a Buick/Olds/Pontiac tranny (2004r) with fairly simple modifications. Preferably from a Grand National. I would make sure your rear end isn't any taller than 3.42-1. Otherwise it will be lugging a little bit.

700R4 are also good choices if you want the overdrive...

personally I wouldn't give up the TH400 for either of them... the TH400 is a far better trans IMO.... I can live with 3 speeds...

the stock rear end in these cars is a 2.28 open...

I like that engine bay! any more pics?

You could put in a 700 but you would need an adaptor plate for the bell housing, more of a pain in the a**. If that's got a 2.28-1 rear that's way too tall for an overdrive. A 2004r and a 3.42 or 3.73 gear set would be sweet.

NOT worth the effort and cost of swapping. You'd end up with a weaker tranny anyway unless you go with a 4L80 (which is a OD th400).

I'd love to do a 200-4R behind my 500 but the cost to get it
to hold up to the torque just isn't worth it.

awesome underhood pic...you should post one of the entire car!