Hi All.  I just repurchased my 73 Vette.  I am told the engine has never been overhauled, and it has approximately 150k miles on it.  Does anyone know how many miles a small block chevy 350 V8 can reasonably be expected to go before needing overhaul?  I changed the oil regularly with Mobil 1 for the first 86k miles.  I don't know how well it was maintained by the 2nd and 3rd owners.  So I guess my question would be whats the highest miles original engine C3 Vette anyone knows about?  That goes for the M20 tranny also.

 

John Reinschmidt

No crystal balls here, John!! It's pretty hard to say with any amount of certainty how long any engine will survive. Granted, one that has been well maintained will last longer, theoretically, but, a lot depends on how the car is driven in between them oil changes!
A compression test, and cylinder leak-down test will give a fairly good indication of the integrity of the engine. Also, pull a valve cover and see how much funk is on the heads. A lot is bad, little is OK. Other than that, it's a crap shoot, in my opinion. If it don't rattle, smoke, fart, puke, or squeal, drive it till it does!
150k is a lot of miles on an older engine, but that don't mean it's worn out. I would start a fund to have for the O/H, 'cause it will likely need one, eventually. When? Hard to say.
Good luck, and congrats on re-owning your old car!! That's a great feeling, ain't it?

It would likely be more cost effective to install a crate engine should yours need an overhaul, but like it has already been said, why do so if the engine is still in good shape. The best reason not to get a crate engine is to keep the car all original if that's in your thoughts.

A '73 small block Vette isn't at the top of the collectibility list anyhow, but what it does have going for it is that it's the only Corvette with the soft bumper in front and chrome in the rear. That does make the '73 somewhat of a one-year special, hybrid or oddity, whichever you choose to call it, but only to those that would matter to.

It's your car and your money. Just think it through and do what you feel is best.

 John, I had a 69 Chevy Pick-Up, that I used for junkin sometimes pull a trailer haulin a junk car.The old boy had 265,000, 3 speed on the tree. I sold it for $500 got it back for junk cause the floor was gone.Pulled the motor,rebuilt it and put it in my 79 Chevy Pick- Up.Sold that truck for a good buck.Wish I had that motor back, their's nothing better than a seasoned Chevy motor!

   Dave

That's kind of what I was thinking.  I would expect if the engine oil was regularly changed, and the engine was not overheated (coolant, radiator and water pump properly maintained) that it should go 200-300k miles.  We'll see!  If it is run out, I will overhaul it rather than get a crate motor just to keep the numbers matching.

John