I don't disagree, but you are really making the same argument I am with the exception of the numbers matching motor's importance for a high dollar type car. What started our discussion was the value or lack there of for a car that doesn't have it's original engine. Some members said it wasn't worth anything other than the scrap metal value (paraphrasing) because it doesn't have it's original motor. I commented earlier because I know the car is worthy of being restored without it's original motor and trans, and I know that if it was restored to a respectable degree that the missing original motor will not affect its sale price hardly at all if it were to sell again.
I've studied B body car prices pretty much my entire life and continue to do so. A matching numbers motor does not affect the price of the car substantially, if at all. It only affects the pool of buyers who would be interested in the car. As long as the pool is still big enough the buyers will be there to purchase a car. The price will be determined by:
A. What the car is / options based on the VIN and fender tag or build sheet (i.e. desirablility and rarety)
B. Quality and condition of the car at sale time
C. Options verified by the fender tag and or Build sheet (some plants didn't list as many options on the fender tag as St Louis for instance so build sheet is more important to those cars i.e. all 69.5 six bbl cars)
What does affect what cars sale is originality in appearance and condition (not necessarily matching motor) if a survivor or quality of a restoration. By stressing originality they mean was it restored or still in original appearance ie no chain steering wheels, velour interior in 60s car, recaro bucket seats, fender flares, cowl induction hood on a mopar, at least an original color, etc.
Some car value sites list default values for things such as add +5% for matching motor, or A/C, or 4 speed etc. That is just an approximation though.
Let's take a car that sales have confirmed is probably a $50K car based on what it is and condition - 5% is $2,500. A $10K car 5% is $500. It's negligible to the likely sale price.
Let's say your car was $10K at sale time when you bought it, if it was worth $10K to the larger market it would still be worth ~$10K to someone with a replacement motor if it looked and functioned exactly the same. Just not to you and probably several members here.
Examples I know something about:
Cars that are nice inside and out and run perfectly mechanically - you would be proud to take to a car show and open up everything.
68/69 383 Road Runner's $30K - $40K
70 383 Road Runners $40K - $50K
GTX hardtop add about $5K (no diff for 70 RR/GTX)
Converts add appox $10K for 69 RR, maybe $15K for 70 RR
70 V code RR or GTX - $55 to really big
The range is affected by trans, options, colors, condition with a must have being title and fender tag. Matching engine barely moves the needle if at all. A missing fender tag car is only going to sell to someone who is new to Mopars and doesn't know that it's important ... unless there is a build sheet.
No way you can restore a 68-70 383 hardtop or coupe RR and make money at those prices unless you are a car restorer or can do everything in your garage, and even then you probably would not break even on purchase price + sheet metal + interior + chrome + etc etc + materials + any labor that had to be sourced. Even if someone gave you the car you would be behind because you could have sold the car before doing anything to it and likely had more money in your pocket than restoring and selling.
Let's say the 70 V Code car is really max desirable i..e plum crazy, white interior, buckets, console, 4 speed, tic-toc, Air Grabber, etc. Maybe close to $100K - then maybe if there were two similar cars and the other being FE5 Red say and one was matching numbers and the other wasn't . maybe, only maybe price would be $10K diff but more than likely price would be affected by other things like manual vs auto, buyer pref, story, etc.
It does not matter to the final price of those 383 Road Runners if the engine is original or not. It matters a little value wise to 6 BBL and Hemi. That only affects some buyers who get into that sort of thing.
