I have a 78 360 I'm about to put a timing gear/chain set into. I've herd people say about straightening up the cam for better performance, because the later 360 was cam timed for emissions. Are they talking about using a straight or off set key way?

You are talking about degreeing a cam. If it is not where you want it then you can adjust it using the appropriate offset keyway to advance or retard it the specified amount. You will need a degree wheel,dial indicator, a piston stop, and some patience.

Always degree a cam when installing it. It is of the utmost importance to firstly, know where TDC is EXACTLY, and second, to have that cam set up from the corrected TDC.

Aftermarket parts are notorious for pushing tolerance limits. Example....a new harmonic balancer on my 79 GT's 360....the balancer was out 2 degrees in the factory markings. I slipped an old Mope balancer on and re-ran the numbers.....the factory balancer was dead-on. I ran the numbers again using a 360 balancer a buddy had.....again the factory unit is spot on.

Back goes the new replacement unit.....run the numbers....still 2 degrees out. The simple fix is a timing tape around the new balancer.

Now....imagine if you just dropeed a cam into this without checking. We already have 2 degrees misalignment with one part....what if the cam is out by a degree or two as well? Then you have the possibility of being up to 4 degrees off of where the manufacturer wants his cam to run at. Then there are the ignition timing issues that would arise as well.

Comp Cams makes a nice kit for under a buck and a half, that allows you to set virtually any engine.

As UCUDANT pointed out....degreeing a cam isn't an overly difficult job, just tedious and exacting. But do it once or twice and you'll get a firm understanding of why it must be done.

Bad

I agree degreeing a cam is good but for most street applications unnecessary.There are not millions but probally hundreds of millions of cars from the factory that never had a cam degreed.If you worked in a shop in the old days where it was common to do chains and cams you would starve or get fired if you tried to do it.Just line up the dots and set the timong when you were done.Now if you want to gain a bit more performance its a good idea but for a guy thats going to do a cam swap maybe once or twice a 150 buck investement for a street motor isnt a wise investment.Rocky

Rocky, like you said I'm not changing the cam, but the new timing set, the crank gear has three different key ways to use. advance, normal, retarded. I'm just trying to figure out the best one to use. I was told that the factory had them retarded for emissions, so would that mean I use the normal setting?

I'd use the advanced setting if you don't want to degree it. It will help build good cylinder pressures, but you'll really never know where your timing is at.

is the engine in the car? do it the easy way,install chain straight up,put compression tester on #1 cyl.,crank engine over with coil disconnected,throttle blades open.then try same with chain in the advanced position.go with the highest cyl. pressure.