American Motors: 1971 owa-4 carb, vacuum secondaries, combustion chambers

Question
I have a 1971 javelin SST 360. Was originally a 304 but replaced somewhere down the line by a previous owner. From the numbers I can find the carb/ intake only match 1970 engines. Having carb problems and would like to replace. Is ther any direct bolt-on replacements that don't require a intake manifold replacement. Just like to get her running at present. Carb overflows and kills engine and float replacement isn't available on the owa-4 carb. Looking at the Holley 1850s 600? Thanks for any help you can offer.

Answer
Brain,
If it is a 1970 or later AMC engine, it should have come with a Motorcraft carburetor. Not a performance carb whatsoever. You can use a  600 Holley w/vacuum secondaries or an Edlebrock 600/650 carb. Both will bolt on and all you should have to do is the basic adjustments. Float level, idle speed, idle mixture. I've used many Holleys in the past. They were prone to eventual gasket leakage. The newer ones, I hear, use better gaskets to prevent this.
What size engine is in your Javelin? If you are not sure, look behind the motormounts on the engine block. You will find the CID cast into the block. You can also find out which cylinder heads you have by removing the valve cover and looking for a 7 digit number cast into the head. 1970 was a good year for AMC V-8 engines. It had dog leg ports and many had the very desirable small combustion chambers (51 cc) which increased the compression ratio. Send me the numbers and I'll let you know. Good luck.
Kevin