Cost of restoring a 1970 Porsche 911

[VintagePhilippe]

Hope you can help guys. I am looking to buy a vintage car for longterm investment purposes. I live in Montreal.

While I am a car guy and love all vintage cars, (even helped my dad restore his 1961 Chrysler 300 a few years back) I do not own my own antique car yet. I am hoping that I can soon buy an antique car that I can restore. It is essential that with time this purchase will prove to be a very good investment. I have two daughters (and no sons!) so it is important that I buy a vintage car that will increase considerably in value in the future.

My wife loves old American cars but I prefer vintage German cars. Ever since I attended a Car Show this summer I fell in love with the 1970s Porsche 911 maybe this is due to my owning a VW Beetle a few years back

I have a couple of questions in mind.

1. How much would I need to spend to restore a car in this condition and how much would it increase in value after it is restored to excellent condition?

1970 Porsche 911 | Blue 1970 Porsche 911 Model Convertible in Brook Park OH | 3220258341 | Used Cars on Oodle Marketplace

2. Would buying a Classic American Vintage be a better investment?

Thank you for your help and feedback!

Philippe