I have a 71 Duster,full interior, steel hood, 73^ disc brake swap. 410 stroker 360, CAST Scat crank, made 467hp and 506 ft lbs on the dyno pulling it to 6k ,727 forward manual VB, 3000ish stall 10in b&m holeshot conv. 4.30 gear, 275/60/15 Et street pro (28ish in. tire)I’m slightly worried about trap rpm and how tight I can safely twist the cast crank, what is a safe max rpm for this crank, and what does everyone think it should run?

Think the 10” converter gonna hurt the situation but that’s just a hunch. I’ve gone 10.80 in Vegas with our “bracket Betty” iron headed 360

Should be fine. If you run mid 11's at 115 mph then the engine will be spinning around 6500 rpm in the lights and the driveshaft maybe spinning at 6000 rpm. 6500 might be a little past your peak power point but it shouldn't hurt anything. You'll just have to play with it and see what it wants. The car might run better with 4.10 gears but no reason to make any changes until you gather some information.

Something like that would be good for 11.50 something around here at 2800 feet based on someone I know who has a later model Duster set up set up kinda similar.

Think 6000 - 6500 would be a good rpm limit. You'll have to run it with those gears and see what you get thru the lights. Too much rpm and a gear and/or tire size change may be required.

I know of people who have broke cast cranks, but they were in cars raced hard every weekend for several years in a row.

At 6000, was it still making power, or had it leveled off ?
With decent valve springs I wouldn't worry about 6500 RPM, but that might not be necessary.

Yep 6>6500rpm with slip although I doubt you'll get too much with that converter.
At a guessing weight of 3400lbs@the line and an honest 450fwhp/28" tyre your ticket could look like this if it hooks good>

60 Foot E.T. : 1.59 Seconds
1/8 Mile E.T. : 7.21 Seconds
1/8 Mile Trap Speed :94.25MPH
1/4 Mile E.T. : 11.43Seconds
1/4 Mile Trap Speed :117MPH
1/4 Mile Trap RPM :6054RPM+slip and with 4.10's 5772+

We got a street/strip Demon here with a mild 340/416 running 11.2's/118+ with similar hp, .500" hyd. cam, stock J heads, TR with 2 x 650DP's, Hughes 3500stall, SS springs, 3.91's/10x28's at approx 3250lbs, shifts@5500 traps@6000-ish.

FWIW, Scat and eagle are cast steel. Certainly stronger than cast iron,but OEM 360 cranks are pretty strong already. Mine have been stock stroke, but I've run cast steel cranks to 7,000 for years. Strokers shouldn't need that much even if they can handle it.

If you knew the weight that would help a little more, but my guess is it'd be right around 11.70s. Could be pushing the lower 11's but I think the 10" convertor will hold it back some and may actually help keep the rpm down a little as well. We ran a 28" tire and 4.56 gears for a little while on a stock stroke 360 with 8" convertor. It was spinning to 67-6800. We later put a 30" tire on it and dropped the rpm down to 62-6300.

It was starting to level off at 6k but I think it might’ve had a couple more hp left in it.

Judging from driving it around this thing twists up very quick, I’m going to guess it will trap between 6200 & 6500 from the messing around I’ve done on the street, but I currently have my rev limiter set at 6k so I’m not sure. The first couple times at the track I plan to leave the exhaust on it so I know it won’t be max effort. I’ll let everyone know what it does once I get it to the track.

That’s good to know. Thanks. I’m probably worrying about the rpm more then I should be, I just don’t want to hurt it after putting the last 4-5 years of my free time into getting this car together.

467 hp on a chassis dyno? If so, I'd expect it to run in the 10s.

I’d be very pleased to see a slip that looks like that! Honestly I was figuring 12.10s-11.80s

It was an engine dyno, I wish it was wheel hp.

Should run mid 11’s easy enough. Would run better with a good convertor.

I would think 11.3 to 11.6 all day pending track condition and the how it hooks

Using the peak HP or peak torque RPM may not be what your motor wants to be shifted at, I learned that on my last pump gas stroker BB motor. It had several different sets of heads on it with a low deck six pack set up, I engine dyno tested it multiple times on three different engine dyno, it always made peak HP between 5500 and 5600 RPM, peak torque between 4500 and 4600 RPM.
At the track it wanted to be shifted at or above 7000 RPM That stupid motor was an over achiever from day one, I learned a lot from it
My message is go test different shift points, maybe start at shifting it at 5500 RPM, then 6000 RPM and then 6500 RPM as long as it is going quicker and faster move the shift point up until it doesn't go quicker or faster by 500 RPM increases, once it stops gaining try splitting the shift rpm by 200 to 300 RPM above and below where it went the best for you. Not all tachs read the same RPM as all other tachs also
Good luck, have fun and test, test and test some more

Nice looking hot rod. Good luck with it!

Being an engine dyno and not chassis dyno I'm going to guess 12.00s.

Well I finally made it to the track for the cars first Test n Tune last Saturday, I was happy with the results considering it was in street trim with the exhaust still on it and bouncing it off the rev limiter on shifts. I still have a lot of learning to do and there are a few minor tweaks that need to be made. These are the time slips from the first 2 passes.

Is it spinning? 60’ is soft. 4:10 might help a bunch. Mine is a low gearset 904, but I run a 26” tire with 4:10’s, with a 9.5” ptc converter that slips 3-4% at the stripe. If flashes to 3500 rpm. Crosses at 6500-6700 rpm using the same crank. I have 1000’s of runs on it and dragweek and 60,000 street miles. It has been balanced to 1/2 a gram by a real old, very picky guy. Oh, with that hp in a sorted out combo you with be in roll bar territory. Low 11’s