Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Chevy Nova Cam Replacement

would the following be a good combination for a 250 L6 73’ Chevy Nova? I am planning on replacing the headers, intake manifold, and a quadrajet carburetor. my only question is would i have to replace anything else for the reason that i would basically be putting new parts in an “old” engine. also, would i be able to replace the cam with the engine in the engine bay? And to add to the info, the engine only has 17 thousand miles on it so i think its relatively in good shape.



I don’t know - you’re startint to talk real time and $$ here - you might want to get it up and running first.

It’s near impossible to say if it will be a good combination or not; there are too many factors involved.

With a cam replacement you always replace the valve lifters, use special cam lube, and break the cam in properly. Failure to do so can severely shorten the life of the cam.

And I still think a Quadrajet may be a bit much carburetor for it. Bigger is not always better, or more powerful.

I’ve been thinking, the engine has so little miles on it, should i even worry about poor performance because of the low miles or should i still be worried because it’s still an old car.

Speed costs money… How fast do you want to go?? To change the cam, you can PROBABLY remove the radiator and grill and slide the cam out the front.

First you will have to remove the water pump and timing cover, exposing the cam timing chain and gears. On the right side of the engine are two covers (I think) They cover the cam gallery and lifters. Remove those too, and the distributer, after the engine has been turned over by hand to TDC. Remove the valve cover and rocker shaft, taking the valve spring pressure off the lifters. Make sure the timing marks on the timing gears are lined up so you can re-install it in this exact position. Remove the timing gear (and chain) from the cam and carefully set it aside. Remove the retaining plate that holds the cam in the block. Raise the lifters off the cam and hold them up with clothes pins. Lift them up high enough so the cam journals will clear them. Carefully slide out the cam. This is not an EXACT detail on how to do this, but it is very close…If you are installing a NEW cam, you should always install new lifters.

Be careful when selecting a cam grind. Most “high power” or “racing” cams perform in the 4000-6000 RPM range. Your engine can not operate in that range without extensive modifications, especially to the head and valves. Look for something with “high torque with a good mid-range” or “A good stock replacement cam with a nice boost in power”. Something with about 270 degrees duration, am I right here guys? Check the horsepower rating for a '67-'68 six cylinder Chevy (any Chevy). If it’s noticeably higher than your smog motor, say 150-165 hp, then see if you can still get that cam from your Chevy dealer or aftermarket…

The Quadrajet will work fine because of its very small primary bores. It will not not feed anymore than your engine can digest. Good luck and HAVE FUN!

thanks for the info. before i asked the question i didn’t really have an understanding how the cam, lifters, pushrods, and related components worked, but after doing some research on wikipedia, i learned a lot and i see how complicated this actually would be, so cams and other such components I’m probably going to leave for the next couple of years, and when i get some more free time, workspace, and money for sure, then i can begin getting more hp out of the L6.