326 or 455 For My LemansMy '67 LeMans is mostly stock, has been in my family since 1977, and was my first car at age 17. I plan to restore the car, but I have a question about the 326 motor. How can I step up the horsepower as it will be a weekend driver? I remember this car being a little underpowered, but if you would have asked my dad in 1989 when he gave it to me, he would have said, "It has plenty of power for you. More power will just get you in trouble."
I'm considering pulling the motor and hanging on to it and dropping in a 455 motor, which I have yet to find. I'm not looking for crazy horsepower, just enough for a 34-year-old to have a little fun. I also thought of beefing up the 326 to obtain the extra power. What would be more cost-effective for the 350-375hp range? Can I do it with the 326 without going crazy, such as boring the motor way over what is needed? Or would that range of horsepower be better achieved with a 455 and minor modifications?
I'm not sure what the 326hp rating was when stock, and I know the 455 rating differed throughout the years. I would like your recommendations on what I could do to obtain the weekend warrior I have been dreaming of.Brett DavisSultan, Washington
Jim Taylor responds:Your LeMans probably has the most commonly installed YN-code 250hp engine. This engine has a "261" carb with 9.2:1 compression. For the weight of the '67 LeMans, I'd agree with you that the car is "a little underpowered."
Pontiac did offer an H.O. version of the 326 in '67 with a "461" carb with 10.5:1 compression. They are very rare today because for a few dollars more you can add the GTO package to the LeMans and get the 335 or 360hp 400 engine.
You mention "dropping in a 455 motor, which I have yet to find." This means you've been looking for one. Why not? It's the brute of the engine series and won't cost any more to build than the 326 engine. The 455 engine only needs to be almost stock to reach your 350-375hp range. A 455 engine is not too hard to find, you just need to ask the right person. Plus all you need is a block and crank, a pair of the plentiful 6X heads, and the rest of the parts can be used from your 326-the distributor, valley pan, oil filter housing, and timing case cover. The '67 timing cover will allow you to maintain the original eight-bolt water pump and pulleys. Also, the dampener can be rebuilt (rerubbered) and installed on the 455 crank. All of your accessory drive pulleys will line up. The power steering and alternator will mount in the same place.
An Edelbrock Performer manifold and AFB-type carb with 750 cfm will provide the power you want with surprisingly good fuel economy. Use a cam with around 224-degrees duration, no more than 0.480-inch lift, and a 112- or 114-degree LSA with around 9.5:1 compression.
You will have a very strong idle with 14-16-inches (hg) of vacuum. You can even use the flexplate from the 326 engine and the two-speed transmission. The natural high torque from the 455 will surpass your expectations for that "weekend warrior." Do it.
Tachin' Up A '67 GTOMy '67 GTO has the standard dash cluster. From the literature I have, there was either a block-off plate installed in the far-right pod or a Rally clock. I have neither, just an open hole into darkness. Is there any way a factory or repro tach can be installed into that location, or do I have to convert to a Rally cluster? I want a tachometer in my dash, not hose-clamped to the column or other such place. Thanks for your help.ScottMesa, AZ
Quint Stires responds:Yes, you can add just a tach to your dash. Many Pontiac parts companies in this issue sell reproduction gauges. Contact one and ask for an "in-dash" factory tach. Once it's installed, the brown wire needs to connect to the "-" or negative side of the coil (run the wire through a grommet in the firewall), and attach the gray wires to any of the other gray wires for your dash lights.