The best I can seem to run so far is 14.5 @96 I am running a Raod Demon 625cfm now and have a friend offering me a Holley 800cfm double pumper. 800 seems like it will be way to big for my motor but he tells me that is made a huge difference on his motor which was close to mine in specs. Any opinions on the size of this carb in relation to my motor would be great.

 

What kinda heads do you have? I'd look at other stuff before you look at a new carb. If its a friend, couldn't he let you try it?

 

Bone stock 882s but I have a set of p/p 186s going in next week.

 

you will see a good improvement with this upgrade.

I'd hold off on the carb and do every thing else first.

The 280H cam needs a high stall and high rear gearing and lots of compression as the power band is up there. Either change the cam down or keep it and... make the rest match it.

3500stall 4.10 gears 10:1 cr ported big valve heads with small chambers (186's are nice) CC them and slelect the right gasket to get as close to 10:1 as possible.
Measure the piston deck clearance when you remove the 882's and go from there.
if you need help with the math......

A performer RPM intake is worth 15-20hp

The HEI will need to be recurved search my posts on this.
(more initial,, limit the mechanical travel)

Althou a larger carb (generally) will make more power you should improve the airflow of everthing else first. then you'd see a gain. with the 800.

Glass packs are very restrictive. The Y pipe is critical.
Uncap the exhaust and see how efficient it is.

Your car should go 12's @105 with these changes.
have the 186's been flow tested? CC'd? they are rarely exactly 64cc.

You'll need some hi traction tires like M/T drag radials.

 

The heads are 62.5cc and I am using a .020 gasket. I recurved the dizzy already. My exhuast is two straight pipes running to thrush packs just behind my doors, are you saying it would be better to run without the glasspacks on? Like running my exhaust all the way back over the wheels and just putting in a cut out for racing?

 

the heads sound good.

Thrush and other cheap glass packs have a restrictive small diameter perforated (louvered) core inside to reduce sound. Trouble is they reduce flow and power output for anything more than a near stock motor.
You can improve here a lot. The car will be quieter and faster as a result.
When the exhaust system is designed right you won't need to uncap it to go racing. I run my car as is, justthe way i drive it. you can too.
If a Z06 Corvette can run 11sec ets without making a deffining rude roar you have a lot of room to work within.
Lets move out of the '60's into the new melenium.

Glass packs are not the way to go. Too loud, too restrictive.
1. You want the muffler(s) as far back as possible.
Behind the axle on a third gen.
2. Third gen cars do not suite a dual exhaust sytem well.
(floor contour, rear suspension.)
3. You can go just as fast as open exhaust or faster with a proper 2(2.5") into 1 big pipe (3.5") that goes over the axle into either two or 1 big muffler with either two exhaust tips or 1 big one.
Will fit and perform a lot better. Can even employ 2 hi flow cats to keep it legal. will support 450-500hp and not be a "heat score".

I suggest you make the mods and then try your car at the track with the exhaust headers uncaped and capped up and see for your self.
Then start over with the exhaust system design.

 

Running the drivers side exhaust piping was a nightmare, I dont want to mess too much with it for awhile...beat my *** good the first go around lol. I am thinking of Heads, gears, stall, carb (maybe) then go another round with the exhuast. Thanks for all the advice.