what are the difference's between the first cs carbs and the later 9000 ones, what are the visual cues if any? which perform better? part #'s. thanks

The Competition Series carbs were manufactured(1969)before the first oem(1971) Thermoquads. Two versions of the CS carbs were made.
An 850 cfm and a 1,000 cfm. For the first year, the CS carbs had press-in jets that were held in place with an o-ring, then the switch was made to a screw-in style jet. These are aftermarket performance carbs that are 'air metered' carbs.

If you are talking about the 9800 series T.Q., these are all 'solid fuel' metered carbs that only have floats, accelerator pumps, pump well cover and transfer tubes in common with the CS series carbs. These are also aftermarket replacement carbs and are 800 cfms. The choke system is attached to the base of the carb and requires a 12 volt source; the choke is much like the current choke on the Edelbrock Performer and Thunder series carbs and is unique to these carbs. This means the choke will not fit any other models with one exception: the Ford 460 '74 T.Q.'s(this was a heat activated choke from manifold heat)without the 12 volt assist. There are 4 versions:
9800, non egr for Gm products(Q-jet replacement)
9801, non egr for Mopar, replaces all cfm's,
9810, egr for GM,
9811, egr for Mopar. All are 800 cfm's.

All 9800 series carbs were known as SuperQuads and used a '74 Ford base with a Mopar throttle lever, a '75 top and a '78-up bowl.

Here are pics of both models and note that the CS series carbs have large rectangular flats on the top with Carter logos and the front vent stack is part of the top casting. **Interesting note is that the one year only(first oem T.Q. use)
1971 340 carbs were based on the screw-in jet CS carbs but was 800 cfms.

A 1,000 cfm CS T.Q. showing only a single primary booster ring and no taper to the primary bores; just 'straight-through' bore:

Here is a pic of an nos 6568 1974 T.Q. Note the attached style choke; easier to adjust than the conventional divorced choke. Also the throttle lever is clearly different and has the Ford kick-down lever incorporated and 2nd driver rear choke pull-off. And the top is always a '74 top, not the '75 top the 9800 series used.

Did all those CS carbs have the angled idle screws? are kits still avalable for the CS?

Yes all of the CS carbs have the angled mixture screws, I keep a stash of NOS and replacment kits on hand for restorations like this one, I'm pretty sure David has them as well.

Is there any advantage in running a 850 cs over a reg 6000 series 850 cfm t-quad. does't seem like any

I ran an 11.12 with an OEM 72 400 thermoquad I paid $10 for at a swap meet. I did use larger seats and did a good bit of tuning.

Got to admit, I have soft spot for the comp. series though.

Jeff's probably done more real world comparison testing than anyone.

Jeff, did you sell the bb a radiator? I did get a radiator for the Demon to suit the 440 swap.

I don't feel so bad now, I lost out on a auction for one, I already have a 6321 (73 400)ready to go with some mods and the good 1966 rods. i guess my 4973 is close to the CS anyway. Talked to Jeff about manifold porting, Thanks Jeff

I agree, nothing wrong with a 6321. If you are still looking for a CS carb there's a decent looking one on ebay right now.

CS on Ebay

1,000 cfms i wonder if it would idle under 1K rpm's