about to start a restoration on a 1970 mach1, 351 cleveland. my motor guy asked what i want to do with it. plan to keep a stock as possible but feel should make certain upgrades. any ideas on upgrades to make without ruining fact car is orginal. only one other owner, mother bought it brand new.
I highly recommend a hydrolic street roller cam if there is one available for that motor (and there should be because they now make them for even the 428CJ). Clevelands need more duration than the factory cam. I agree with the headers comment and would suggest FPA coated headers. Is your motor a 2V or a 4V? I would use the 4V heads or aftermarket heads along with the 4V intake or an aftermarket intake. I liked the '70-71 4-V heads although the compression might be tight for pump gas. Those quench combustion chambers do add torque. Even the stock 4-V intake is not bad for the street. Also, even for a stock or near stock cam, you will want a higher than stock stall converter. Ford made a 2400 RPM converter to put behind their heavier 351-4V cars in '72 and '73. Clevelands don't make much torque at lower RPMS because the port velicity is too low. Finally, if you want to keep up with the newer cars, you may want to insure your gear is no higher than 3.25:1. Also, if performance is important, you can get a 408 cid stroker kit for less than you might think. That longer stroke helps torque and the extra cid helps with the intake velocity of the larger ports in the 4-V heads and larger runners in the intake. Oh, and of course, if you use real 351C ford heads, you will need them modified by your machine shop so that they can live with unleaded gas (hardened seats, maybe stainless steel valves, etc).
Btw - if you want it to look stock but you use aluminum intake and/or heads, just paint the aluminum parts the same Ford blue and most people will not notice. If you have to bore that motor then be sure you use a fan shroud to keep it from overheating. That was a sometimes issue with my old '71 with a heavily modified 351C-4V. today I have a mostly restored/modified '70 Mach 1.