I'm currently looking for a Cadillac 500 ci to replace my 331 in my 55 fleetwood. Also need a turbo 400 tranny. 1970-72

I'm sure a lot of guys are guarded about their powerplants and their sources...however, I find it hard to believe that nary a soul has offered up a suggestion for this request.

There are a few online services that cooperate with salvage yards across America. Try a google search using "parts search" and you should get a plethora of results for these services. Some of these charge fees, some dont.

Personally, I would search every salvage yard within a reasonable driving distance. You might be surprised about the likelihood of finding a diamond in the rough.

I was strolling through the engine building of a boneyard one day asking about big blocks....when one of the yard guys said that he had his eye on a gem...but didnt think he would ever get to the project. I inquired further....

He points to a big blue behemoth in the back corner of the room. Come to find out, a 71 eldo was wrapped around (literally) a pole - leaving only big blue (literally). It was obvious that she hadnt gotten very far before the chance encounter....she was very clean...and intact.

The moral of the story was that after breaking it all down...it was in fact, a very low mileage, complete 500, right out of that car (er horseshoe)....the yard had been saving it for a special customer, then the yard guy, then cash-in-hand prevailed.

Stick with it...there has to be some in your area. I have found a couple here and there since to snag pieces and parts off of. You may have to settle for a piecemeal approach as the rodding business has taken a likin to the big caddies of late. Good luck.

You almost need to look for a salvage yard that has the older cars. Many yards scrap out cars after they become a certain age, to make room for later model stuff.

i got a 500 , 425 and a 472 for sale

You also need to know how to identify a 500 versus a 472. cad500parts.com has a section in their catalog about the identity thing. Not much difference in power I would think.