Nylon teeth, who thought that was a good idea? Brings back memories. GM Ford and Dodge all did it at that time. Bought a 3/4 ton pickup 402 in 72 and a 3/4 ton 454 pickup in 74, changed cams a few years later, I don't remember nylon gears on them, mainly SB's. The GM camshafts used in those days, I'm told by a cam builder the GM cam lobes were not hardened enough for long life and durability on flat tappet cams. 390HP 427 camshaft not available anymore from gm, it was a good cam for the 396 402 engine. It would be interesting to know what trhs75 has in his engine. Bought many camshafts from Oregon Cam grinders without issues, Also Summit cams without issues. Interesting comment from a guy on cam chain lash, (with a socket on the crank I go by feel off the Harmonic Balancer) he pulled the distributor cap, moved the crank with a socket turning the engine backwards, he would replace the gears and chain if there was more than two degrees slop watching the dist rotor movement. That works I guess.

 

The cam gear itself was not plastic. It was an aluminum gear and then they had put a plastic nylon coating on top of the teeth. Steel gears and double roller chain is probably the best way to go. I guess a gear drive is another option but I heard they're pretty noisy. And can cause a lot of spark scatter.

It does eliminate the noise from the timing chain. But my cars always had exhaust systems that overpowered any noise coming from the timing chain.

 

I was told my 427 had a replacement cam (possibly the cam from the 400hp engine?). I'm still trying to figure out what the problem is. I welcome your kind advice, everyone. Thanks!

 

It may be time to check the firing order. There's a set of wires you can swap and it won't backfire at low speed but runs like crap at high speed. I've seen this before.

 

If it has the braided shielding on the plug wires, the inner insulation may be breaking down under high load conditions. Might be time to replace the plug wires if you haven't already done so. The shielding is to help prevent radio noise. If you don't care about that you can get unshielded ones.

Also could be a cracked insulator on one or more of the plugs which is breaking down under high load also.

 

Thanks for the input! I have labeled the (non-shielded) plug wires according to firing order diagrams I've seen, but I'm not sure how to know if the wires are attached to the distributor correctly. I did replace the plugs after I noticed the problem, so they should be good. I can certainly replace the plug wires sometime, also.

I'm not sure how to check the inside components of this kind of distributor, or the (transistor?) box that attaches to it.

 

You will need to rotate the engine until the number one cylinder is at top dead center on the firing stroke. Then look at the rotor with the cap off and it will be pointing to the number one cylinder on the cap. Using that as a reference, then you can plug the other remaining wires in according to the firing order.

 

When you do this, pull number one spark plug and put a finger in the hole to make sure you are on the compression stroke.