I am working on a 57 Sedan de Ville with a 365 in it. When it came to me, I did the normal things to get it running, check for compression, fuel, and ignition. I got it running and it ran pretty well. Ididn't run it very long as the cooling system was drained. While cleaning up, the gasket scraper I was using slipped and hit a head bolt and it MOVED! On further investigation I found broken head bolts on both sides. I removed both heads and took them to.my local, old school, machine shop. Both heads are cracked in the same location. The third cylinder back (#6 & #7), the crack curves between the valves. Now to my question. I understand that the 57 castings (1465406 & 1465431) are prone to cracking, and are difficult to find. What heads should I be looking for to use as replacements? I have seen the 58 - 62 heads and the 63 390 heads available but I need to know what is simplest to use as replacements.
Probably 95 percent of our members here play with the 472/500 engines, so you might not get the answer your looking for right away. Not to discourage your search, but just be aware this is predominantly newer engines on the forum. Good luck in seeking your information and welcome to the board. Tom
Thanks for the reply. I am looking for the info on multiple forums. The info will find me sooner or later.
Non-Expert Guess: All engines from '48 to '67 use the same head bolt pattern, exhaust port layout, and intake port layout. The newer you go, the higher-horsepower and larger displacement the heads would have been used with. As long as chamber size doesn't become excessively large to achieve the desired compression ratio, I'd select the latest-model-year heads I could find. Might also get you larger valves--which is likely a bonus.
I bought a pair of 59 390 heads along with the rocker assemblies (the rocker shaft stands and the shafts ARE different) and head/exhaust manifold bolts. After a stop at the machine shop they will be ready to go!
Last update, the 1959 390 heads worked out perfectly! The engine runs pretty well for just a valve job and a rear main seal. Now moving on to bodywork and paint and wiring and interior and.......
Let's see some pics... If I wasn't a horsepower junkie I would have left the old 365 in my 56 coupe in there... But torque won my vote..
Looks like a big project. Keep going, and thanks for the engine info. I also have heard that the later the engine the bigger the valves. I have a 62' 390 that's a basket case I one day want to rebuild and place in my 57'
