Well guy's I'm back at it again. help me build 9.40 car out of what I have. 500 rb cid,13:1 ,Indy - 1 fully ported heads,the car is 3300lbs with diver. ladder bar coil over,13/31 slicks' 4.88 gear. 5500 CONVERTER. YOU fill in the blanks?. what cam ? what center line ? in @ WHAT ? What headers size ? what carb ? oh yeah this in an A body. would love to hears some proven combs. would love to hear from some builders on this . ok guys let them fly !!!!!!!

Head flow numbers would help, but your cam will be up there in lift, probably close to .720", and for induction, if budget allows, a tunnel ram and a big stall convertor maybe a 5500. Otherwise I see low 9.80's out of that combo, but not 9.40's..

get some boost, that will do it. no need for 5500 stalls, 4.88 gears big lumpy cams or the like. Buddy runs 174+ in the 1/4 w/ a small block tube chasis car and 12 lbs of boost with a 4000 stall and 3.73 gears. Car will run low 8's at 200 when he feels like running the full 1/4.

heads flow around 370 . no dyno .

B1 original or M/C heads, I always smile when someone says they get 370 CFM outta Indy-1's. I'm sure I'll get crap for that comment....ooops!

Getting all you can out of the heads you have is key. Notching the bores by the intake valves will probably help. My 4.5 bore 528 makes good steam with a 440-1 head. A roller cam is a definite must. If you can get a gross lift of .800, that will net you a lift in the .750 range due to lash and deflection. Good pushrods and very stout valve springs that have good harmonics (i run comp 947) will keep it all happy . Obviously you will need some very good rockers, or they won't last.
A good baseline cam would be the Isky RR735, used with a 1.65 to 1.7 rocker will get you the duration and lift to make the power. This cam has 280/288/110 specs, I ran mine at 110, but you might want to try 108 installed to start. This cam, with a 1.55 rocker got me the 8.77 et in my sig at 3000 lbs.
I would be tempted to go with a 2 1/8 by 30 by 4 inch header, with 6000 stall. Get more compression in it if you can, my motor has 15.1/1. My heads are cut to 62cc.
I run methanol, but have been told that gas can do as well if you are willing to spin the motor some.
I run .043/.043/3/16 low tension rings, and a vacuum pump.
Set up your final drive ratio with a little less gear, 4.56 tops. If you can switch to a 14/32, better yet.
I know this is a lot to change, but getting 840 + hp is not going to be easy, but is doable.
If you have to go into the shortblock, I like more cubes, like 512 in a low deck or 528/540 in a tall deck aftermarket block. You can then order the pistons for the lighter rings.
I run a terminator injection system on methanol. Pretty bullet proof once you learn how it works. Very wide tuning window with alky.
I also run the Indy 3x intake, which I think will fit your plans well.

Jenny Craig the car.

Looking at other cars, like 440Jims, you could go as fast as 8.90s if you want to spend the $$. It IS possible.
An example of a car that uses every bit of the heads he has is my neighbor Chuck Lofgren went 9.68 with an SR headed 499, full dress 3800 lb 70 Cuda. And that was at BIR, where the air is rarely below 1800 DA. Take 500 lbs off that car, better air, and you are looking at close to 9.0s
Just putting my 528 /440-1 combo in your car would net a 9.0 on a good day, and with the last mods, should have potential to push a car as heavy as yours to high 8.80s.
Latest mods besides the larger intake valves are crank scraper and 1/2 inch pushrods from Manton.
It is basically how light do you want to make your wallet!

I'm not much help but I'll sell you my 9.40 AMC for 15 grand..

My 500" low deck is a bad mis-match of parts that we had and still goes 9.80's in good air. The cam only gives 150 cranking compression, hope to change cams soon but it is nice running on pump gas at 11.9 compression. 440-1 heads with Proparts headers, through the exhaust on a 10.5" tire, 1050 dominator, 8" converter, 4.30 geared Dana, 3200 pounds.
With the right cam in your combo and careful parts picking 9.40's are within reach especially if you give it some compression. I'm also shifting at 6600 and trapping at 6900, I'm sure my heads would like more RPM but that's where I'm keeping it.

I honestly think my cam is the is the missing link.All the cam companies I have talk to said that my cam is they would sell me.706/693 274/277 @50 cut on 108 in @103.the best I got out was 10.40 move it to 106 and it went 10.05.Do you guys think this cam is holding me back ?

I honestly wouldnt expect mid to low 9's out of that combo.
There is a few things you could go with to help out. Most people find a vaccum pump picks them up a decent amount.
Also, I agree with the suggestion of alky injection. A fly'n toilet or Terminator will be good for a .15-.2 or so. Even on a moderate compression engine like my 11.8:1 440-1 engine the injection picked it up half a tenth plus down low...60ft that is.
Fact is it takes a good effort to run 9.40's with 440-1 heads at 3000+ lbs... Im sorry but 9.70's isnt no where close to 9.40's. I would guess and say near 100 hp is need to go from 9.70's to 9.40's. Well this is my experience with at least 2-3 engine combo's i have run utilizing those heads. I always let the performance at the track do the talking.
I would personally have 15:1+ alky injection and lighten the car up some.