I had a Mopar brand 2.77 low gear set installed in my old pump gas Duster, that worked well with 3.73,3.91, 4.10 and 4.30 running 315x60x15 M/T Et Street Radials and the same size ET Street bias ply tires with that 400 stroker motor with both the 4.25 stroke crank and the longer 4.300 stroke crank later
That car ran 127.+ MPH with the Eddy RPM CNC heads and pickup to 134.+ MPH with the M.W. size Indy SR with a Indy 400-3 intake and several different 1050 CFM Holley Dominator carbs corked up with the air cleaner on using 92 octane OR pump swill from Bend
I haven't used the TF270 heads yet and I don't know how they compare to the Indy SR M.W. heads non ported
The 4.250 stroke will move the mass a lot easier than the SB motor will with a 4.00 stroke in a SB 340 or 360 motor
Good luck on your new build

I'm running a 512 in my 'cuda. I'm restricting power as I built the engine combo for our local track series where streetcars are limited to 11.00et's.but on a prepped track it'll go 10.5's. I have 325x50 ET Street R's on a 8 3/4 4.3 geared Detroit locker with old school SS springs & old Comp Eng 3 way adj shocks.. It puts 645 HP to the rear wheels, runs 1.5 60 fts & usually tops out at 125 mph..

Calvert split monos and Cal-tracs work really well. Buy the best double adjustable shocks you can afford, but the Calvert 9 positions will work fine to begin with.

You don't need a lot of gear with a stroker. I would do the 3.73's.

I am almost finished with my 511” stroker and need to start thinking about the back end of the car.
It’s street strip and I know I’ll get a few different opinions on this. Combo is
511
11.6 comp.
TF 270 heads
Indy sp ported 1050/4150
2 to 2 1/8 header
265/268 .660 on 108 solid roller.
4 speed

It’s a Cuda. I plan a 1” spring relocate and a 9”. I want a 29.5 or 30” tire.
I don’t know what leaf springs and cal trac? My thoughts are a 3.73/3.91/4.10
Gear. I’m thinking it should trap around 130?!
What would you go with for suspension and gear?

Do you have the rear yet? If not you might be interested in the S60 that I'm pulling out of my Duster. I'm going to sell the S60 plus the wheels and tires. It might slide right under your car. It has 4.10 gears and a Detroit Locker along with disc brakes.

That’s impressive power. What’s the combo? Is this a stick car? Also does it too out due to being out of RPM?

Do you remember the spring length to use with offset shackles?

I'm assuming 2.66 1st gear 833. At least the 4.10 probably could run a 4.56. If street driven Cal Tracks. Good shocks, bias slicks. The clutch better have some slip. If not the 833 may not have a long life span for track use. If it was an auto 3.91-4.10
Doug

according to Porter the 270s make identical power to a cnc 295.