dyno time,lets hear the guesses.

[olds307 and 403]

Interesting on a small carb with high compression and nearly 400 ci. Here is two Olds 350's bored to 4.100", both 9.7 to 1, both hydraulic roller cams, 1 degree duration difference. The really difference with low end torque with 750 cfm with only a slight improvement in torque, horsepower is the same.

 

[64nailhead]

I agree with it needs a more carb. But I’ll say 428hp/438 torque.

A 750/780 carb would add 30hp.

How hard did you lean on the timing and AFR?

 

[Malibu795]

I agree with it needs a more carb. But I’ll say 428hp/438 torque.

A 750/780 carb would add 30hp.

How hard did you lean on the timing and AFR?

~100/100 HP/TQ short😉

 

[64nailhead]

~100/100 HP/TQ short😉

I didn’t notice the other pages of the thread.

But respectfully to melloelky , I dont buy those numbers because of the carb. Unless the carb has been worked over to flow more. 650 or 670 cfm isn’t going to give up those numbers IMHO.

 

[Malibu795]

I didn’t notice the other pages of the thread.

But respectfully to melloelky , I dont buy those numbers because of the carb. Unless the carb has been worked over to flow more. 650 or 670 cfm isn’t going to give up those numbers IMHO.

I'd be curious to know what the intake manifold vacuum was during the run.. knowing carbs/throttle bodies are rated at 1.5inHG vacuum. If the vacuum is higher than that are the RPM limit then the carb is the restriction.

 

[melloelky]

I didn’t notice the other pages of the thread.

But respectfully to melloelky , I dont buy those numbers because of the carb. Unless the carb has been worked over to flow more. 650 or 670 cfm isn’t going to give up those numbers IMHO.

and that's entirely possable,i do apprecate the feedback from everyone that's for sure as i don't know enough about the subject but it was a piece of mind seeing it run before taking delivery.I'm not living and dying by the results either,i'm just hoping for a fun engine that stays together longer than the last one did.

 

[64nailhead]

and that's entirely possable,i do apprecate the feedback from everyone that's for sure as i don't know enough about the subject but it was a piece of mind seeing it run before taking delivery.I'm not living and dying by the results either,i'm just hoping for a fun engine that stays together longer than the last one did.

Glad you didn’t take offense to my comment.

My experience (limited) with 500hp ‘s is you need more head and cam, but an 850 carb doesn’t hurt.

Regardless of my opinion, that’s worth nothing truly, is I’m sure you’re in the 425-475 range. And anything over 350-400 is a screamer. No one can tell the difference between 350-500hp on the street - my opinion.