511” stroker! Rear suspension&gear selection.

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?

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.

My only worry about the 3.73 is that it’s harder to launch with taller gears. Although I’m switching from small block to big block so it may be different.

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..

Cab, according to Porter the 270s make identical power to a cnc 295.
I had 3:55 behind the small block and I had to slip the clutch a lot to get out there without falling on its face.
Switched to 4:30 and it was much easier. Sounds like I’ll be fine with whatever I choose. I won’t be going for ultimate ETs anyways.

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

I forgot to mention that Duster had ladder bars and coil over rear suspension with single adjustable Strange Engr. rear shocks that I change to double adjustable later, which where well worth swapping to
I also had two different converters, a 10 Inch Contintental at first until it broke and then switch to a older type 727 T/A 8 inch SS/HA converter which was a ton better than the larger 10 inch Faster and quicker and easier to drive at the track and on the street

Cab I do remember your old duster pretty well. I loved that car. Do you still have the b5 Cuda?

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

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.

Yes, I still want to sell it also so I can finish the new car, 1965 Dart back half car

AndyF, ideally I need a b-body width 60”, but I could go as narrow as 58” and use a 15x8 with 3.5bs. Let me know I would absolutely be interested. And I’m not too far from you.

No, car is an auto with a loose 8" converter. Its a 400/512 stroker, Stage 6 MW heads with an 850 QF carb on a Super Victor manifold, runs on Pump Gas.

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

I use 20" front segment springs but keep in mind mine is a '63 B-body and, on those cars the spring length is the same as an A-body. Not going to be the same as yours.

Call Calvert Racing and they can walk you through the proper selection for your car.

I believe the 1st gear is 2.47 or similar. I don’t know what clutch to run yet. That will be one of my next questions.

That really doesn’t sound like something I would say(not in that way at least).

Our pump gas 512/400 made 770hp...It was a beast....I like the Indy EZ1 325's for this combo....Gearing & tires should be set to hit the traps at 6500-6600max...Love the 71 Cuda posted above by the way!

Mine is an auto 512 street car, BUT I had 3.54's for a long time & the car ran ok, 4100lb 11.04 @ 123, then went with Stack EFI & still sorting it out,,, fuel delivery problems, that said I went 4.10 & it made it VERY happy just cruising the streets, the 410 is MUCH better for drivability , I have Caltracs, split monos, & sliders , & had MT Radials 325-50-15 R, now I have Hoosiers Radials, with a stick shift I would say go Bias tires ,, I forgot to mention I do have an Overdrive A518

I always cringe just a little bit when I read that a phord diff is going under one of our Mopars. I have ran an 8 3/4 behind my 499 wedge and my 540 Hemi for 15 years or so. Plenty of track use with drag radials with the 499. Ever few years, the rear would get noisy on the street and need a ring and pinion. But never had one fail running 6.8s in the 1/8.

Given the cost of a complete 9", is it cost effective? Couldn't you build a tougher 8 3/4 for less money, or a 60 for a little more. Or couldn't you replace ring and pinions in the 8 3/4 a few times before the cost of the phord diff is covered? Anything to keep the phord stuff away form our Mopars.

Duane this was your quote. From a trick flow 270 thread. I was a little off. Would you mind explaining a little more in detail? I apologize

It’s not really that much different of a head than a ported EZ head.......like an EZ295.

Power should be very similar if the heads got swapped on the dyno

I already have a Mark Williams center with 40 spline spool lined out for a good price. I didn’t like the idea at first. But it’s growing on me.
I don’t have near as much faith in a 8 3/4. Stock for stock I would, but this will be far from it.

Seems pretty self explanatory.

What I said was speculative........ “power should be very similar”.

You made it sound like the test had been done, and the results were that the power was “identical”.

I knew I wouldn’t have said it that way.

Until someone actually does the test........ how close the power would be between those two heads is an unanswered question.

Duane I apologize for mis speaking. I assumed by what you said you’ve tested 295 combos and they made similar numbers to 270 combos. I can admit I got it wrong. But it wasn’t intentional. I’ll be more careful with my words.