Dyno'ed two of three engines so far, one with 606 hp, other with 631hp. The engines were all just rebuilt with all the time in the dyno. Is that much of a difference in numbers pretty common?

That's about 1%!!!
Pretty darned good, IMO.

I would think your average hp would be more important.


Would 25 hp say at 3500rpm make a difference in throttle position???insynk?

1% You Might Want To Recheck Your Math

that's what i was thinking

more like 4%.

I agree with strip. check avg.

hawk 511ci bored to 551. 1050 diminators, same carburator was used for all engines. 2rd engines came in around 632hp. If i put the 606hp engine in th center wouldnt it be ok?

nevermind 3rd engine came in around 632 hp

Should be within 5hp. 10 at the most.

Head porting differences (whether they are as-cast or have had port work done) will account for a few hp difference. CNC ported heads, cc'ed chambers, and individually degreed cams will result in very very little hp diff between otherwise identical motors.

30 hp is more than you'd like to see.

Leakdown test the low HP engine? Any other differences?
Oil pressure, water temp, oil temp, BSFC?