318 driver - cam change or not?

73 Duster 318/904/2.76 gear. Rear tires are 225/70-14's. Just have a 7 1/4 rear so no tire-burning. I am primarily interested in around town punch and am trying to decide if I want to change the stock cam or leave well enough alone. Engine bone-stock 74 318 with 40,000 original miles. I have removed smog devices and re-curved distributor 12 deg initial, 36 total all in by about 2800. I do have dual exhaust off of the stock manifolds and I have a Performer intake and a 600 Edelbrock carb. to install. I'm going to replace the timing chain when I do the intake/carb swap and the little voice keeps telling me "you're going to be there anyway so why not bump the cam up a little". I keep hearing horror stories of guys having cams go flat with the new oils and I'm just not sure how much gain I would get, considering how I drive. I also would prefer not to lose any gas mileage. Thanks in advance for the help.