455 Olds or 472 Caddy

[koolkat269]

who has swapped either one of motors in? I am trying to decide which motor to put into my 61 GMC Suburban. I already have a 69 472 with an Edelbrock intake and electronic ignition. I have a lead on a 455 with a factory aluminum intake. Would like to see some pics and what you guys had to do to install them like if you used headers and any other parts.

[Chevy Fleetside]

If you already have the 69, why not use that. There are some sources out there for caddy engine swaps. I have some catalogs for it as I was thinking about doing that and I believe the 69 472 has 375 hp. http://www.cad500parts.com/catalog.htm Just in case you didn't know. I heard that if you put aluminum heads on the caddy engine it weighs the same as a SBC. This is what I heard. Oh yeah.. and expensive too.

[jonzcustomshop]

my 64 gmc had a caddy put in it. It looks like they trimmed the cross member, and firewall to get it in. radiator was in the stock location, and they used an automatic (I assume out of the caddy). It also has a tilt/telescopic and a late model power steering box on it, also maybe out of the caddy as well.

[koolkat269]

Originally Posted by jonzcustomshop

my 64 gmc had a caddy put in it. It looks like they trimmed the cross member, and firewall to get it in. radiator was in the stock location, and they used an automatic (I assume out of the caddy). It also has a tilt/telescopic and a late model power steering box on it, also maybe out of the caddy as well.

Wow, so it doesn't just drop in.

[Chevy Fleetside]

If you look at the link posted, it might have a kit that uses a different oil pan. http://www.cad500parts.com/catalog/page5.htm Lots of good info on that site. Get out your reading glasses and go to school.

[urmyboyblue]

I had a 455 Olds in my 65 C10. I had to fab custom engine mounts and clearance the fire wall to make it fit. However, you might be able to use late 70's chevy truck engine mounts off of a truck that came with an Olds diesel engine. The fire wall clearancing was more than just hammering the fire wall, too. After you do that, it fits pretty good. You can use 68-72 Cutlass headers but you will have to clearance the frame slightly. I ran a custom oil pan, so I cannot say if clearancing the cross member is required. But remember that an Olds has a small pan- they don't hold much. So you may want to buy a larger pan anyway.

The only thing that bothers me about Caddy engines is that they used cast iron rods. In normal service (keep the red line at stock levels) that is not an issue. However, if you are going to hot rod this thing, you may want to consider the added expense of engine upgrades before selecting one of these two engines (both have suppliers of parts but are niche markets that leads to higher prices). It might be better to sell what you have and look for an SBC.

[koolkat269]

Thanks guys for the info. I guess I will be going with a 355 that I have. Easier drop in and it's new. And thank you for the link, I did order the catalog.

[chevyrestoguy]

A 472 Cadillac or an Olds 455 would both make for an outstanding truck engine due to their excellent torque making ability. The downfall is that they aren't a plug-and-play and if you want to hop them up a little, aren't cheap. Another great option is a Pontiac 389/400/455. They fit a little better and the aftermarket has more performance stuff available. In my opinion, GMC should have stayed with the Pontiac engine, but they decided to go with the V-6 in the '60s.

If your Caddy engine is strong and you don't mind a little fab work, that would be a cool swap. But, I totally understand staying with the 350 as well.

A buddy of mine had a 500 Caddy in a very nicely done mid-60s Ford F250, and that was a trailer pulling beast. The torque of the Caddy would pull a loaded car trailer with very little effort.

[rcrahn]

I once saw a Caddy in a square body....It looked sweet and sounded great