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Chevy Resto Tech - October 2014

We answer your Chevy restoration questions

Mark Lundquist Sep 3, 2014
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Tip of the Month

After a long-time project was completed, it was time to fire the engine for the first time. It was a mild-performance engine with fairly decent horsepower and torque. Little did I know the deep cycle AGM battery wasn’t up to the task and an overnight charge with a conventional battery charger didn’t fix the problem. This is a common mistake. Switching to the new breed of Optima charger configured to handle the task brought it back to life and saved my wallet a trip to the parts store.

The need for speed usually involves torque and horsepower, and along with power comes the need to start the engine and keep it running. Deep cycle batteries like the Absorbed Glassmat Batteries (AGM) are hard to beat for a reliable source of deep down power and reserves, but with the advanced power comes some special charging options to keep that cranking power at its peak. Although AGM batteries can be charged with a conventional charger, they can struggle or fail to bring the AGM back to life if the voltage falls below around 10 volts. The AGM battery might need the special treatment only an AGM charger can provide. Optima has developed an all-purpose charger than can handle the AGM’s special needs, but can also charge and maintain any conventional flooded battery.

Optima has not only come up with a series of all-purpose battery chargers that can bring back those AGM batteries (and also maintain a full charge during storage), but it also now has the Optima Digital 400 battery maintainer (not shown), which acts as tender. Check out this new generation of specialty chargers at You won’t be sorry you did.


I was a Super Chevy subscriber for a few years back in the mid-to-late ’80s when I owned my Royal Plum ’67 Impala SS from 1982-1998. I still have a box full of those magazines. A year ago I purchased a ’68 Impala Super Sport. My ’68 is Butternut Yellow with a black vinyl notchback roof with black interior. It has bucket seats and console with all the correct SS door panels, and the interior is all correct. The front marker lights say 327, so I’m assuming it is a 327, but all small-blocks look the same, no? It is an automatic two-speed Powerglide transmission with a 10-bolt non-Posi and 3.08 gears.

I was wondering about the engine and if it is, in fact, the correct one to the car, if it really is a 327 and if so, what horsepower? I have not taken the valve covers off to check any head stampings. Here are the numbers:

Serial no. 164478J213744

In front of the passenger-side head on the block deck: 18J213744V0220H0.

Back of the block by the transmission bellhousing on the driver-side: 3914678 (p.s. not sure if the 6 is correct. I couldn’t see very well. I was using a flashlight and a mirror and it didn’t look very clear in the stamping, but I think it’s a 6.)

If you could give me any information on the serial number, trim tag, and engine numbers that would be awesome. I love your magazine and hope to see more fullsize Chevys in future issues.

Darrell Zimmer
Via email

The only anomaly I see in your numbers is the block deck numbers. The first digit is probably the number 7 instead of the number 1. During stamping at the factory sometimes the numbers and letters are a little weak and hard to read. With that correction, the engine number matches the VIN number making it the original engine. Good news. A numbers-matching engine can make a huge difference in the value and bragging rights. But the casting number is the gold standard for decoding the engine. The suffix code on the front pad can be restamped, not like the casting number. Casting number 3914678 checks in at a 327, either 250 or 275 horse. In your case it matches the specs for block casting number 3914678. More good news. Looking at the suffix code on the front engine pad, you show the last characters being H0. Since the stamped numbers are hard to read at times, I would suggest it reads HC, which would make sense, making your 327 the 275hp version. Thanks for your letter. Seems like you have one nice ride. Enjoy.

Got a restoration question?
Send it to: [ m ] Super Chevy, Resto Tech, 1733 Alton Parkway, Suite 100, Irvine CA, 92606. [ e ] [ f ] 949-705-3423



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