And now a word on hidden Horsepower

[Mr 5 0]

Agree with PKRWUD here.

Replacing the ignition parts with new stuff won't hurt a thing but tests have shown that most 'High-Performance' ignition parts do little to really increase power. Reliability and possible improved gas mileage is the usual result.

I would recommend using what I use with good results; Stock distributor (very efficient) with fresh rotor and a brass-terminal cap, Crane PS-91 coil, Taylor Spiral Pro wires and Autolite plugs, changed every 10,000 miles.
The hotter coil, quality wires and fresh cap/rotor should supply plenty of spark to ignite the mixture in those aftermarket heads. Dead-on reliable for me and never an ignition related problem with this set-up.