I need a couple of 850's for a tunnel ram application. 500 inch hemi, unported heads, .600 flat tappet, street/strip deal. Summit list two 850's. Not sure of the differences. Can anyone tell me which is better suited? I realize it will need changes either way.

https://m.summitracing.com/parts/hly-0-9380

https://m.summitracing.com/parts/hly-0-4781c

The choke/no choke is the only difference I notice

That's the only difference I see too although I didn't look at them very long.
I'd probably run the chokeless carb but it'd be better to have the whole choke tower milled off.
If you can spend more, the custom built carbs are nice too, there's no extra cost to have them built for your combo through a place like Summit.
I had 2 Quickfuel 750's on my low deck TR, they had the wedge shaped TR floats in them and were pretty much spot-on right out of the box.

I wouldn't use either of those models. Spend a little more money and buy modern aluminum carbs with billet metering blocks so you can tune them.

The 9380 is a race carb from 30 + years ago and it works with a K&N stub stack but I've been using these lately and there great.
https://www.summitracing.com/parts/hly-0-80804bkx/overview/
https://www.summitracing.com/parts/hly-0-80805hbx/overview/

I converted my 12.5 race gas 500" 440 to E=85 with this one
https://www.summitracing.com/parts/hly-0-80845hbx/overview/
perfect out of the box!

You want to get something with adjustable metering for a tunnel ram, they need the idle circuit calibrated different that for a single carb app. Quick Fuel Q-850's or Q-950's would be my suggestion if you want to keep cost down, otherwise custom from a quality company would be my suggestion.

Mark, im going for an old school build/look here. What would it take to make a dichromate carb work well in this application? I know it sounds strange, but i really prefer a traditional looking carb for this build.

Well you could use the old school carbs and then buy a set of billet metering blocks and have them anodized to match the old dichromate look.

Otherwise you need to plug the idle jets in the old blocks and redrill them smaller. You might also need to add transition slot jets and maybe drill and tap the main body for adjustable air bleeds.

on my older type blocks, after i drilled the IFR's out (carefully, the jets ended up pulling out and i didn't even drill the blocks) it was already the size needed to thread for the brass set screws. 6-32 i think they were.

Thanks guys, im not ruling out Quickfuel based on the replies here. Just weighing everything first.
Im sure they are not as tunable as modern stuff, but have any you guys messed with a pair of old 6109's?

I wouldn't hesitate to use the 9380 on tunnel ram, you might have to adjust the idle mixture screws and maybe do some jetting for your area gas and altitude How much tuning and modifying are you willing and capable of doing?
Are their better ones out there, sure if you want to try them or have a custom set made

You just need the idle feeds and idle air bleeds threaded to be able to make adjustments. With an old school carb the metering blocks get threaded for a 6-32 x 1/8 brass set screw, the bodies vary but usually the idle air bleeds will go an 8-32 x 3/16 set screw. You can thread the main air bleeds for 6-32 as well, but usually the old school bodies are OK as is with the calibration. If you get the old style carbs and don't want to do that work yourself I can thread both the body and metering blocks, set you up with blank set screws to tune with and a starting calibration. And even billet can be made to look old school...

I would not even consider anything that has a choke horn or isn't tuneable.