have a 63 327 factory four barrel engine and markings on the heads are a rectangle with a triangle. any help with the specs?
Pull the valve cover please and post the casting numbers inside. rectangle and triangle don't tell us much. These are all camelhumps. These are powerpacks: but without the casting number I've nothing to look up.
You have a 250HP a327 and yes, it has the PowerPak heads. They have 1.72/1.5 valves and about 60cc chambers. A lot of people will tell you they are junk and to throw them on the scrap pile. I disagree, for a mild street build they are not that bad, especially if you want to maintain a stock or near stock appearance, great heads for even a fairly hot 283. The small runners and valves really boost low end mixture velocity and make the smaller cubes produce some low end TQ. In a light car with some gear they can be quite effective on the street and they really help a heavy automatic car with highway gears. A friend warmed over the original 250HP in his '64 SS by doing some mild port work, carb tuning on the stock 4GC and recurving the distributor. He slipped in a Summit 1103 cam and with the PG and 3.36 peg leg it would do a nice little burnout and had NO problem keeping up with traffic, he managed to beat a Trans Am with a TPI 350. The guy in the TA was surprised to say the least. He then swapped in a 200-4R and 3.73 posi which really gave it a kick in the butt, it runs pretty darn good for an old "sled". Traction with stock size tires has actually become an issue.
Wouldn't the 416 casting 305 heads be a better fit for thier 58cc chamber, 1.84/1.5 valves and unleaded seats?
I have a set of 416s on the shelf. For a 302/305/307- sure. a 327?... *maybe*... for anything larger they breathe like a 40 year 3 pack a day smoker.
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