When is too many miles "too much"?

[Nvidia]

So I bought this 1986 GT awhile back (May or so). Haven't driven it at all yet, as the brakes are totally shot.

Anyway, when I got it, the speedo said 29,300 miles. Since it's from 1986, I'll automatically assume the thing's been tampered with, or it's been rolled over at least once. Although 29,000 original miles would be nice.

So my question is, when is it time not to invest any money into the engine? 150k miles? 200k? 100k? I have a chunk of money I'd love to put into it, but why put it in the engine if the block's got less than 50,000 miles left on it anyway?

Am I better off saving the money and putting it into restoring the interior/all the other things that are wrong with the appearence, or perhaps investing in a new block?

Thanks for reading, appreciate it.

 

[HISSIN50]

A well maintained motor at 200K can be stronger than a poorly maintained one at 50K.

A compression and/or leakdown test would be very revealing in discerning what you desire.

Good luck and congrats on the new (to you) ride.

 

[Foxfan88]

If the motor is weak, just give it a nice rebuild and you should have a fresh start....

 

[89stangalang]

Its all in how the engine was maintained and treated over its lifespan.

 

[Daniel50]

compression test is the answer on how you engine is