Devalue: Non numbers matching

Started by Bob Kielar, October 02, 2022, 09:10:51 AM

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Bob Kielar

I have tried to keep our 1955 Cadillac Fleetwood as original as possible. Unfortunately the engine block has cracked in several internal places and can not be repaired. My question is how much does this devalue the car?
Bob Kielar
Keep Cruzin
1955 Cadillac Fleetwood


IMO, not very much since the CLC does not match numbers such as Bloomington Gold.  Perhaps if it was an Eldo Brougham or 50s Eldo my answer would be different. 

I was surprised when we started attending the ACD Festival to hear how many cars in that Club have been rebodied and/or rebuilt from parts and pieces of other vehicles.  Tuckers too. 

In both the CLC and ACD, similarly Olds Club, Buick Club, etc., having non-matching numbers does not seem to carry much stigma for the year and model. 


I'd say it depends how you fix it/proceed.
If another '55 motor/block or from that family is used, not much.  Just keep a record with the car of what was done and why, rahter than try to slip one in on a seller.   
If you stuff a LS7 and trans in, it's substantially modified and a different animal.
Value is determined by how much someone(s) is/are willing to pay for it.  If you're keeping it, then no harm, no foul just cost of ownership increased.

I say this will become more and more common as these cast iron blocks age.  So not uncommon in the scheme of things.   A lot to do with the design-o-day that promoted thermal stress cracking and period metallurgical practices.
Block cracks can be repaired by various methods also, so not necessarily a throw away but may cost more to fix.  Stitching, welding, and/or "sleeving" are possible in most cases but require art and skill.  Those repairs depend on the extent of the damage.  If the left bank is broke off, not likely.  Without the technical mumbo-jumbo, cracking is one of those once it starts hard to control things too.  So prolonging is a better word than permanently repairing.

Jon S

Numbers matching is a Chevrolet term especially in Corvettes. Remember even in the day, Cadillac replaced engines if they were bad.

1958 Cadillac Sedan De Ville
1973 Lincoln Continental Coupe
1981 Corvette
2004 Mustang GT

2 Devilles

If it's a muscle car that has different engine options, it means something....A 1970 Chevelle can have anything from a 140 hp straight 6 to a 450 hp 454, so that is important in cars like them.  In our classic Cadillacs, I don't think it matters much, if any, just so long as the engine is from the same year.  I didn't even bother to ask or check when I bought my Coupes, just knew the '60 had a good running 390 and the '70 had a proper 472 when I bought them.
Lucas Johnson

1960 Coupe Deville
1970 Coupe Deville
1972 Mach 1 Mustang
1974 F100 2wd
1977 F250 Highboy
1994 F250 4x4


hmm, it appears my comment yesterday was eaten . . .

number matching seems to matter for things like muscle cars likely to blow an engine ("hey, see, *this* one survived!") and for things with a wide variety of options, where the "desirable" ones were uncommon to rare, as noted by 2 Devilles.

A 65 mustang that *came* with the K engine (more powerful v8) and a four speed is seen as more desirable than one that started with 6 cylinders and an automatic but later had a strong V8 and a 4 speed bolted in.
1972 Eldorado convertible,  1997 Eldorado ETC (now awaiting parts swap from '95 donor), 1993 Fleetwood but no 1926 (yet)

David Greenburg

I agree that with these cars, it's possible that the original matching numbers might make it worth a little more to some buyers, but most won't care as long as it's the correct engine for that year. The only caveat might be with convertibles (especially with years like '59); if you replace the engine in a convertible with a non-convertible engine, it might raise suspicion that it's not a factory convertible, but as long as the chassis serial number is there, even that shouldn't make much difference. Leave the matching number stuff to the muscle car guys.
David Greenburg
'60 Eldorado Seville
'61 Fleetwood Sixty Special

Art Gardner CLC 23021

It doesn't really devalue the car.  It does mean that a few buyers won't buy it, preferring a numbers matching car.  But most buyers won't care, as long as the new engine is also from the same year. 

For your particular case, since you still have the broken block, I recommend that you clean it up really well and paint the outside carefully.  Retain the engine block for that day when you do want to sell the car. For most buyers, they won't care.  For the fussy ones, you can include the block with the sale of the car.  That shows that the car is still original, even with a replacement engine block.

Art Gardner

1955 S60 Fleetwood sedan (now under resto)
1955 S62 Coupe (future show car? 2/3 done)
1949 S60 Fleetwood sedan (restored 30+ yrs ago)
1958 Eldo Seville (2/3 done)