I know what you're saying , but I'd expect a 5,000 stall to be too tight for this motor. My old 446" used a 5k stall w/ smaller heads and a lot less cam.

Seems reasonable and my 470 junk loves my .680-.660 276-281 @ .050 ISKY solid roller both street and strip for many trouble free years in the 9's and a blast to drive.....

Am I crazy or is 7000rpm with a stock 440 block going to crack the mains?

In over 20 years of running 8.60’s-10.40’s I cracked one block and that one was a 500 inch Stroker engine with 440source billet main caps. No concrete, no girdle. Now I did crack several 440 forged cranks and got to the point if I got 3 years out of them they went on my scrap pile

Probably not, especially with a good balanced rotating crank assembly and a decent tune.
Detonation is the major cause of cracking the main webbing in 440 blocks, not RPM

I would have never bet that my 15-1 comp 572 would need a 6100 converter. 5700 was to tight. Unless you're talking Q16 there us no reason to run C16. I've had zero issues with Renegade 114.
Doug

Question: Assuming two engines make the same peak HP, what's more stressful on a bottom end?
a) 7500 RPM with a 3.75 stroke (451)
b) 6500 RPM with a 4.25 stroke (511)

Not meant to be a quiz; I'm curious about what's more likely to put the hurt to a marginal block.

Personally I think bob-weight will play a bigger hand than stroke - in the last 511 I built - we got the bob weight below 2200 grams using the 7.1 rod and a 4.25 crank in an stock RB block - I also believe in aluminum main caps. The first 511 stroker I built with stock rod journal and rod length had a bob-weight of almost 2500 grams - it beat the stock main caps to death even with studs.

If its a light weight assembly and well balanced and not running into detonation- 7500 RPM does not seem to make much difference

FWIW...

3.75 x 7500 = mean piston speed 4688 ft/min; max 7363 ft/min
4.25 x 6500 = mean piston speed 4604 ft/min; max 7232 ft/min
4.25 x 7000 = mean piston speed 4958 ft/min; max 7788 ft/min

https://www.racepagesdigital.com/pi...ctive-forces-at-work-inside-your-engine/

I guess this is probably a dumb question, but can you calculate the max piston speed without knowing the rod length?

Also I think what really matters is max accel/decel

Me thinks the rod length has nothing to with the piston speed, the stroke and RPM does though
I've heard that the rod length makes a difference on the piston speed at when changing directions on the stroke at BTDC and again at TDC but I've never understood that thinking
I can understand the cylinder wall loading differences between a short rod and a long rod with the same stroke

Rod length affects dwell time at TDC & BDC; not required as an input for mean & max piston speed calculators.