<strong>1:15 p.m.:</strong> The Atomic EFI throttle body has a square bore (think Holley carb) bolt pattern. Most aftermarket intake manifolds have dual bolt patterns, accepting both spread bore (Q-Jet) and square bore (Holley) four-barrel carbs. If you have a GM or AMC manifold, you may need an adapter. We were able to reuse the carb studs. If you have a Q-Jet or Edelbrock carb, you’ll need to replace the long bolts with shorter ones. Snug the bolts in a criss-cross pattern, but do not overtighten them.