I have a SBC in my roadster. I've been looking forward to putting some aluminum heads on it. The block has ID code 3970010 on the left rear of the block. Apparently this indicates it's a 350ci. The suffix code on the right front of the block is "TDS". According to two internet sources this ID's it as from a 1980 pick up, 170hp, manual trans. The head casting numbers are 14014416. This indicates the heads are from an '80-'86 305ci with 1.84"/1.5" valves and 58cc chambers. All of the aftermarket heads that I've been interested in have 64cc chambers. If I were to put 64cc chambered heads on it, it would lower the current compression, which doesn't seem very high to me to begin with. The car runs like a stock 350 and sounds like a stock 350. It's hard for me to believe it has higher compression. I was looking forward to bolting on some aftermarket heads but I see no point in it now. It seems like this would lower the compression enough to cancel the other benefits of a performance head. Suggestions?
Flow numbers have a bigger effect on power than compression does. But even more important is matching everything in the engine to each other, and to the car and it's gearing. Are you also planning to change the cam to take advantage of the improved airflow of the new heads? And then, change the gearing to take advantage of the higher RPM that the engine will make power at?
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