ok. I thought I had my winter drivetrain project for my '66 all laid out: new roller 302, ported GT40P heads, RPM intake, and Comp XR262 or equivalent cam, with an AOD & mild stall plus gears in the 3.25-3.5 range. I'm shooting for a 15-20k miles/year daily driver setup with a balance of good power and economy. I have all the parts on hand except the gears, torque converter, headers, and the $300 camshaft. Today I ran into a couple of deals too sweet to pass up. I'm picking up a Comp XE268 cam and a set of Windsor Jr heads for a steal. I'm thinking they're a little much for my application, but the 'more power' devil is always right there on my shoulder yapping away. Besides, the heads are ready to run (other than me doing a little clean-up porting) so I won't have to have valve guides and springs for my GT40Ps, and I won't have to buy expensive "P-head" specific headers. So I'd like to hear from folks who have run similar combos with overdrive transmissions. The 3.25 gear will put my highway cruise in the 1900-2100 range. Do you think the Jr's and 268 cam will have enough bottom end to pull that efficiently or would I see better fuel efficiency with a little more gear? Or should I resist the the little devil's siren song and go with the original plan?