Crusader 350- 89 Octane?

[davescarrs]

I have twin 350 Crusaders (454's) on my 1987 Trojan. The Crusader manual indicates 89 Octane fuel. I have been putting in the 87 I think (the lowest Octane at my harbor I am guessing is 87). I will now switch to 89, but has anybody else used 87 Octane and noticed a differance?

[rossjo]

Why risk it? 350HP is pretty strong for a 454, and it needs 89 Octane, or it will knock. Saving $0.10-$0.15/gallon for 87 isn't worth the trouble of replacing burned heads/valves/engine in the future, is it?

I run 89 or better in my 454/370HP ... wouldn't consider less.

[prowlersfish]

You may not notice any difference but you engine may I would use the 89 or better . Like Rossjo said with 87 it may knock and you may not even hear it . Spark knock can also damage pistions .

[alexander38]

there's an 88 sting ray on hard in our marina that wished he used 89 and not 87 both motors have bent push rods from spark knock .