I need a pan for my '66 425. Does a pan for a generic 455 big block bolt to my 425?? If not, where can I look for the 425 pan?
Second question; What transmission does my '66 Starfire 425 have? I need to order the typical tranny fluid replacement kit and I don't know what to order or where to find it.

I'm new to the 425 Olds big block and don't have a clue! I'd appreciate feedback!!

 

Yes. The two motors are externally identical.

 

Thanks Joe; I don't know much about 455s; am I limited to an Olds 455 pan, or could I use one from a Chev 455 also? If I'm limited to an Olds, does the model year matter?

 

The Oldsmobile 455, or any other Oldsmobile V8 engine, shares almost no parts in common with any Chevy engine. This is explained in more detail on the 442.com site here.

I suspect that, as you familiarize yourself with Oldsmobiles, most of your questions will be addressed in that F.A.Q. The main index is here, and even this forum's own reference pages use it as a primary source.

 

You need a big block (400, 425, or 455) pan from any year.
I believe the small block (260, 307, 330, 350, 402) pan would fit with some "modification" with a sledgehammer for depth, but I'm not completely sure (never tried it).

The Olds 455 is NOT the same as any other division's (Buick, Pont.) 455. The oil pan will not fit.
Chevy did not make a 455.

- Eric

 

Until the late 1970s, each GM division used their own proprietary engines. Despite having common displacements, these engines had nothing in common (except the distributor cap and rotor). Different castings, different bore and stroke, etc.

Within the Oldsmobile engine family, ALL 1964-1990 Olds V8s have the same oil pan rails. Any Olds oil pan from those years bolts to any Olds block, but as noted the big block pans have a slight difference in that there are a pair of "bump outs" just forward of the sump. Since the forward part of the pan is the same this isn't due to crank clearance, so the only thing I can think of is that it was done to improve oil drainback. In any case, any 1965-1976 big block Olds pan will work.

 

You guys rock! That's everything I need in order to get a pan that'll work. Many thanks.

 

Sadly, the other host of the Olds FAQ is no more (as is the case with the Olds WIKI site).

For those like me who simply don't want to use the one on the **** site, there's an archived alternate version that works for now:

http://web.archive.org/web/200208201...ds/oldsfaq.htm

Just don't take everything you read there as gospel.