I have a chance to buy one that is still in the car and complete but it is rough. The car has been outside in a junk yard for 40 plus years with the hood closed and the air filter on but lets assume it is locked up and has freeze damage. (worst case scenario) What's it worth? Just the motor.
I want to build one a little at a time. No hurry. Can't freeze cracks be fixed reliably enough for street use?
Its probably not cracked, I pulled a 58 plymouth out of a yard in the same condition, it had been sitting since 66 with the air cleaner on it. Its 318 spins freely and there are no cracks i've found. Odds are in your favor, squirt some oil down the spark plugs and see if you can rotate it, don't do much, you just want enough to see if its locked up or not. 55 has the good hemi heads, rebuild it with 10:1 compression, a mild cam, the hot heads 4 barrel intake and enjoy. Just for reference, i'm rebuilding my 392 the same way and i'm looking at a little over 4k for the rebuild.
you have to look at it as a core, it could be good or total junk. I wouldnt throw more than 500 bucks at it, and id try for more like 300. if its been outside for 40 years its probably more like froze and filled with rodents like HRP said. be ready for an expensive rebuild. I wont do another one without being able to inspect everything first before i buy it.
Whatever scrap metal goes for in your area.. if it turns over maybe a little more,, it cost no less to rebuild a 331 than a 392
It may be different these days, but when I did my avatar about 20 years ago, 331 pistons were very hard to find and twice as expensive as 392's. The same year I did the hemi, I also did a 350 SBC for my boat; the complete rebuild on the Chevy was $1100, the pistons alone on the 331 were $1200! The last hemi I bought was a 331 truck engine that I heard run and had good oil pressure, compression, and didn't run hot. I gave $1500 and was happy. This was about 8 years ago.
Comes down to condition and what your end goals are. If it is free and not cracked - probably $500 to $700. If it is frozen - about $300. But - also keep in mind that it is expensive to build an early Hemi - so think about what you want in the end? The heads are probably what we call the 'triple nickle - 555' ones - so they're good flowing heads for a performance build (with some work put into them) - they'll work on a 354 or a 392 with intake manifold spacers. If you just want a hemi and don't care about cubic inches, then this initial core will cost you a lot less than a 392 core - like 1,500 to 2,000+ less. If you want a big cube engine - then you can step up to a 392. If you're thinking that buying it and reselling it are your goals - then don't buy a 331, much harder to sell, than even a 354 and worth a fraction of a 392.
I feel lucky to have found the 331in my area. I don't believe I've ever seen a 392 for sale that's not already built. Maybe I'm not looking in the right places. Anybody in the north Alabama area that has a complete buildable 392 for less than a grand feel free to send me a message.
The 55 331 is an excellent engine and they can run with the big dogs if you have the right pile-o-parts. If you are on a budget then a lot of the eye-candy can be eliminated. The oem 4-bbl intake is an excellent design and can be modified for better flow with a big(er) carb. Forged pistons currently run in the $800 range (as least from us) and camshafts can be reground. Some of the 'extra' expense can come from properly rebuilt rocker arm assemblies, but the results are worth the cost, imho. Save even more money and use the stock water pump assembly. I would not worry as to whether or not it turns over. If it does, great. So, what's it worth? Only you can decide but if it was in my shop there would be an $800 tag on it assuming a crack free block. And yes, cracks can be repaired but the cost of repairs must be deducted from the core value. .
331 short bell housing with good oval heads is a great find. All you have to do is bore 1/8" over and you instantly have a 354. Pistons can be had. If it has the extremely rare 331 4-bbl intake, that is worth +$300 all by itself. I would snap it up in an instant for $500, still give it a really hard look at $1000.
The '55 will have the dry everyday 4 bbl manifold. The '54 is the one year only 4bbl manifold with thermostat
...and boring a 331 out just to use 354 slugs is wasting a good block. I'll make all the oversize 331 pistons you want and you'll never need to worry about thin walls. ....yeah I know a guy that knows a guy that bored out a 331 and used 426 Hemi pistons...yada yada yada......internet crap. .
Don't chase cubes, do the smallest overbore you can, punching the block out to its max means it can't be rebuilt again, which IMO is a short sighted decision for a few cubic inches. I went .030 over on my untouched but worn 392 so if I need to do a total rebuild again in the future, I can go further (after checking the walls).
I had Ernie Hashim (legendary 60s hemi guy, first guy to break the 180mph barrier in top fuel as I recall) bore my '52 331 1/8" over 20 years ago. It had a bad scratch in one cylinder from a broken snap ring so I had no choice, no way to clean it up well enough to use oversized 331 pistons. Ernie said it was a conversion he did all the time, never had a problem with it. He found me two sets of good used 354 pistons from which he made one good set, fit them to the engine, balanced it and I have been running it ever since. Has over 60,000 miles, never any problems. I doubt 426 pistons would be a good swap!!!!!! I do admit to posting a lot of internet crap though.
...very nice Willys.... I do think that you, and your block, are the extreme exception and not the rule. I always check, and always recommend that everyone else check, the wall thickness before ever cutting any cylinder. We have seen way too many core shift problems to ever blindly bore an EarlyHemi block. .
I'm sure Ernie checked before going to the mill but he said the old hemi blocks took this mod in stride most of the time. Just a note to people who might junk a block that could be easily salvaged and made good again.