Re: GMC V6 engine compression ratio
I am still working on the rebuild. I have switched gears since that last post. I have a set of 351 magnium heads, intake and exhaust manifolds ready to go on it. This did cause a problem. The combustion chamber volume of the 305 heads is 100cc and the volume of the 351 heads is 120cc. This will bring the compression ratio down to 6.8:1. To make this work I had to purchase custom pistons from Arias Piston Co. That set me back $700. They could not guarantee any more than 8:1, because of the size of the thier stock piston forging. The big V6 has a large compression height and wrist pin dia, which limited the dome volume. I will know in a couple of weeks when they come in. If you think this is a waste of money, keep it to yourself, this is a hobby not a business. Desk Top Dyno predicts about 275 HP and about 325lb-ft of torque. I will take some pictures and post them later.
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1968 GMC 305 V6 3/4 4x4 Stepside
06 Corvette Daily Driver
Dallas TX
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