How much HP will 24lb injectors be good for? I already have 24lb injectors and mass air meter, a 65mm TB and an explorer intake and am looking to get another engine because I am starting to get lower oil pressure after the engine warms up. I want to keep it fuel injected rather than switching to a carb. Any advice on 306, 331, or 347 for an old guy that won't race the car and really want a dependable engine with more power?