Numbers Matching Question

[chevelle_ss_502]

I posted this same question over on a couple other boards and was wanting the opinion of you here as well whats your .02 cents worth on it?

A friend of a friend of mine has a 68 Z28 that he has owned for a very long time and has finaly decided to sell. At first i was told about the car being a numbers matching 302 4 speed car. As we talked alittle more my friend told me the the motor had been replaced shortly after the car was new because of some problems, but it was all done at a dealership and replaced with another 302. I guess what i am asking is how much will this hurt the value of the car? They are asking a pretty high price for the car but in this day of crazy price muscle cars they will probably get their asking price. I am not wanting this to be a for sale ad, just our talk got me to thinking and i wanted to ask those "in the know".

Thanks
Andy