Rebuild or replace?
Still having issues with the cooling on my 67 Dart GT convertible, 273 4bbl, 904, 7.25 3:55. Still getting way too hot on 20+ mile runs, and burning oil. Pretty sure there is corrosion in the block that’s preventing flow, and likely a head gasket issue (some oil in the coolant).
Torn between seeing about having the 273 rebuilt (to the 273 Super Commando 275 hp specss) or getting a 408 stroker with about 400 hp.
I assume a pull, rebuild, and reinstall will run me around $3.5-4K ish, while prices on crate strokers seem to be right around 6k for just the engine, no labor.
Car is just a weekend cruiser, but is also dreadfully slow as is. My mechanic described the engine as “tired and worn”.
Guess the big question is whether the rest of the components will handle a stroker, and if changing to the bigger engine would increase or decrease the value of the car?
First;
Weekend cruiser, to me, implies put it in drive, sit back, enjoy.
So 50 hp will do that.
How did you get to 408stroker/400hp from there?
The 67 273/904/355s , with 4bbl added, and the 3.55s, should make a very nice weekend cruiser;
if you can get rid of the cooling problems, and get the ignition timing sorted out, which may be partly to blame for ... Both the heating and the dreadfully slow,
and maybe the carb is responsible for the oil-burning, possibly.
So before you spend a ton of money, how about doing a few tests to see just how tired that 273 is.
I mean it is entirely possible she is worn out,IDK, but the tests will prove it.
The First test is a Compression Test. in if the numbers are even then that speaks to a good thing. If the numbers are 150 or better then the engine is NOT worn out. If the numbers are 110 or lower, she's toast. From 130 to 145 is a bit of a crapshoot. So;
the next test is a Cylinder Leakage Test. Numbers less than 4% are excellent They say over 20% is worn out, but the truth is over 10% is already lazy, in your 9/1 Scr 67 2bbl 273. At 9/1 the factory pressure was 135 +/-15. .
Overheating on a 20 mile run could have other sources than the cooling system. And those same sources could be what's making her so lazy.
Obviously , oil-burning is usually a symptom of a tired engine, but every once and a while, it ain't rings. And when you combine all of your symptoms, you might have to do some digging.
In any case a fresh 273 could be about 190Plus hp , which is plenty for a weekend cruiser, with 3.55s; at 50 odd ft above sea level. If you gotta get inside it, a lil boost in Cylinder pressure might be all it takes.
This is not to negate anything anybody else has said thus far. There have been lots of good ideas presented.
