[Pearlbluebird]

Engine is a 455 with 62's flowing around 245 cfm at 28". Cam is a solid grind around 600 lift and approx. 255/260 @50. Carb is a 750 4150 HP holley with a performer rpm intake.
On the chassie dyno it spun 480 hp at the flywheel.
My question is " How much of a gain do you guys think this engine will see by putting a 1000 HP holley with a single plane intake ?

[screamingchief]

Talk about loaded questions...

Here's one back @ ya'.

Which single plane intake are we talking about here???

Also,do note that I'm not a big fan of the HP carbs,lotta hype IMO.

With a nicely port matched victor and a well done 4781/850 holley I would say maybe 10 to 15 HP gain.

Use the same basic victor intake with the dominator flange and a 1050 carb and I'd say up that to a 20-25 hp gain.

With a port matched torker II and the bigger 850 carb,I would'nt expect much change at all,maybe 5 hp at the most,but likely it would be a draw against the RPM with just the bigger carb.

But what you may be gaining in one area,is likely just being traded against something being lost in another area.

What I would do first,just put the bigger carb on the RPM intake and maybe try some spacers as experiments (if you got room to do so),then make decisions and go from there,if the combo responds to spacers that add open plenum space,it will likely respond to a single plane intake as well.

JMO/HTH.

[hungry69bird]

with that much lift more head flow would be benificial i'd think.

i'd think that would make more of a diff than intake or carb

[screamingchief]

Originally Posted by Pearlbluebird

On the chassie dyno it spun 480 hp at the flywheel.

This comment had me for a moment or two...

I'd hafta figure it was 480 hp @ the rear wheels,not the flywheel,if it were at the flywheel something was seriously wrong with that combo.

On a chassis dyno the differences may be even harder to quantify.

Track times would be better IMO too.

[smagnotti]

that motor should be making more like 515 hp at the flywheel depending on its tune.
If its only making 480hp now thru a manifold like a performer rpm, than switching to a single plane type might only pick you up 10 hp, but it will bring up the peak HP point by some 400 to 500 rpm if its a victor manifold swap.
But first you need to find out where your lagging HP went to!