my buddy broke a camshaft on his 502 procharged motor.we put a new cam in and can't get it to run right.at 8 degrees base timing his egts come up over 1300 at 1500 rpm.the only way to get the egts to come down is to crank the distributor 20-25 degrees on base timing which gives it over 40 totall.any suggestions?what would happen if camshaft gear was off 1 tooth?

If you don't have them line up correct it will run. You could have it advanced or retarded depending on what way its off.
When I was a youngster I learned this the hard way. I lined them up using the wrong marks on a chain that was setup for +4 -4. Ran fine until you got on it then it did not have enough power to plane out. I have never done that again, I use a degree wheel now

Dagah2x has same thread. Here's my response posted there.

Did you use the jumper wire to lock the distributor timing when setting base timing ? If not, you are trying to set it off computer induced timing and where very retarded when at the supposed 8, now seeing 50 you are probably closer.

Anyway - use the jumper wire technique and bring rpm to specified amount. I forget this rpm off hand - someone needs to chime in on this.